<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2024 Workiva-->
<!--r:ee1e8a07-0868-45cc-99d3-5b3fc417f72d,g:84168775-06f0-4e7d-a3ec-4d9944a70a0f-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://composecure.com/role/Cover" xlink:type="simple" xlink:href="cmpo-20231231.xsd#Cover"/>
  <link:definitionLink xlink:role="http://composecure.com/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityListingsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityListingsTable_4f7822c9-74ce-463f-9536-f36e288a29a4" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityListingsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityListingsTable_4f7822c9-74ce-463f-9536-f36e288a29a4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_0c761bb6-4a64-4b7d-8406-392c0f9d99c7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntityListingsTable_4f7822c9-74ce-463f-9536-f36e288a29a4" xlink:to="loc_us-gaap_StatementClassOfStockAxis_0c761bb6-4a64-4b7d-8406-392c0f9d99c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_0c761bb6-4a64-4b7d-8406-392c0f9d99c7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_0c761bb6-4a64-4b7d-8406-392c0f9d99c7" xlink:to="loc_us-gaap_ClassOfStockDomain_0c761bb6-4a64-4b7d-8406-392c0f9d99c7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_51a52e37-8dea-4f3c-b941-ffa4b44beb83" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_0c761bb6-4a64-4b7d-8406-392c0f9d99c7" xlink:to="loc_us-gaap_ClassOfStockDomain_51a52e37-8dea-4f3c-b941-ffa4b44beb83" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_ab991725-08ca-4d2f-b4ce-2e66fcf889c9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_51a52e37-8dea-4f3c-b941-ffa4b44beb83" xlink:to="loc_us-gaap_CommonClassAMember_ab991725-08ca-4d2f-b4ce-2e66fcf889c9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_b14e58fb-d918-4dd4-b90c-6dffaab85964" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_51a52e37-8dea-4f3c-b941-ffa4b44beb83" xlink:to="loc_us-gaap_WarrantMember_b14e58fb-d918-4dd4-b90c-6dffaab85964" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_8993ce3c-c502-475b-a39d-46323d8b316d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_51a52e37-8dea-4f3c-b941-ffa4b44beb83" xlink:to="loc_us-gaap_CommonClassBMember_8993ce3c-c502-475b-a39d-46323d8b316d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_ebb4e3e4-9d26-4c76-9976-8539fb392dd2" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_DocumentType_ebb4e3e4-9d26-4c76-9976-8539fb392dd2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentAnnualReport_52e09e40-a0ba-4d0f-bcf6-eb3b4f327b47" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentAnnualReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_DocumentAnnualReport_52e09e40-a0ba-4d0f-bcf6-eb3b4f327b47" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_aa719b87-f8c1-4b95-b385-374e15fbcf01" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_DocumentPeriodEndDate_aa719b87-f8c1-4b95-b385-374e15fbcf01" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_53fbcb89-f12a-4667-962c-966e16238dd2" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_CurrentFiscalYearEndDate_53fbcb89-f12a-4667-962c-966e16238dd2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_803be146-b43c-4a90-99ea-068370a2db63" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_DocumentTransitionReport_803be146-b43c-4a90-99ea-068370a2db63" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_c681c30a-102e-470c-a9d3-3c91e8654c98" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityFileNumber_c681c30a-102e-470c-a9d3-3c91e8654c98" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_7cb51dfd-3784-472d-977f-049fcc833814" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityRegistrantName_7cb51dfd-3784-472d-977f-049fcc833814" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_f0854e78-da19-4859-85b1-4e7e4104536d" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityIncorporationStateCountryCode_f0854e78-da19-4859-85b1-4e7e4104536d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_530e52d7-c970-4adb-a8b6-f3821ed4fc79" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityTaxIdentificationNumber_530e52d7-c970-4adb-a8b6-f3821ed4fc79" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_4750ab0b-d0e6-4ba4-baa6-472e09a89b09" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityAddressAddressLine1_4750ab0b-d0e6-4ba4-baa6-472e09a89b09" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_87639294-80e9-448b-921b-6bd9165e5001" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityAddressCityOrTown_87639294-80e9-448b-921b-6bd9165e5001" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_e4a1aba9-9f92-4d94-ad24-99b9d1017e53" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityAddressStateOrProvince_e4a1aba9-9f92-4d94-ad24-99b9d1017e53" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_4bf3311d-1b0b-4486-8b26-6bf360f40528" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityAddressPostalZipCode_4bf3311d-1b0b-4486-8b26-6bf360f40528" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_8636b667-ba00-4820-9295-a93ba48d47a2" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_CityAreaCode_8636b667-ba00-4820-9295-a93ba48d47a2" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_43348eeb-2dc3-4969-9dff-0ba7cb7d55a4" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_LocalPhoneNumber_43348eeb-2dc3-4969-9dff-0ba7cb7d55a4" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_cfb7d326-39a5-451e-92b6-02834eff0f82" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_Security12bTitle_cfb7d326-39a5-451e-92b6-02834eff0f82" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_632115a4-ac50-4a4a-9b8d-f5946c9e205e" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_TradingSymbol_632115a4-ac50-4a4a-9b8d-f5946c9e205e" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_f71b4a9c-864c-4aca-8990-8c771206cfb6" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_SecurityExchangeName_f71b4a9c-864c-4aca-8990-8c771206cfb6" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityWellKnownSeasonedIssuer_1cdb3347-f8a3-4bc3-bb8c-2fc284ea5e8e" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityWellKnownSeasonedIssuer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityWellKnownSeasonedIssuer_1cdb3347-f8a3-4bc3-bb8c-2fc284ea5e8e" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityVoluntaryFilers_18a9b067-e065-474c-9863-10950980519f" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityVoluntaryFilers"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityVoluntaryFilers_18a9b067-e065-474c-9863-10950980519f" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_4499d0e0-76f5-4800-ace5-afb29386315e" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityCurrentReportingStatus_4499d0e0-76f5-4800-ace5-afb29386315e" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_5498f241-b051-4498-be0b-3acccc767c8b" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityInteractiveDataCurrent_5498f241-b051-4498-be0b-3acccc767c8b" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_d066f808-d569-4695-9657-cd494fa1729e" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityFilerCategory_d066f808-d569-4695-9657-cd494fa1729e" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_4138a292-ec0b-4acd-8c09-ab0b05fac019" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntitySmallBusiness_4138a292-ec0b-4acd-8c09-ab0b05fac019" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_db140bde-c4b7-40ec-a41b-9bb599be3472" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityEmergingGrowthCompany_db140bde-c4b7-40ec-a41b-9bb599be3472" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityExTransitionPeriod_7c0a5afc-8719-4166-aebf-5a1dd1836194" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityExTransitionPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityExTransitionPeriod_7c0a5afc-8719-4166-aebf-5a1dd1836194" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_IcfrAuditorAttestationFlag_922a2f7b-90fa-4a13-98ae-b6dd8d0f5599" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_IcfrAuditorAttestationFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_IcfrAuditorAttestationFlag_922a2f7b-90fa-4a13-98ae-b6dd8d0f5599" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFinStmtErrorCorrectionFlag_e20555d9-a9d0-4f68-b377-8507c8045329" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentFinStmtErrorCorrectionFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_DocumentFinStmtErrorCorrectionFlag_e20555d9-a9d0-4f68-b377-8507c8045329" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_d9ef0080-0ebc-44fa-b2fc-065427d22df1" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityShellCompany_d9ef0080-0ebc-44fa-b2fc-065427d22df1" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityPublicFloat_64b6fbec-eed1-4d42-a896-2bffe5aa113a" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityPublicFloat"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityPublicFloat_64b6fbec-eed1-4d42-a896-2bffe5aa113a" xlink:type="arc" order="29"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_c808c822-e537-44bb-8df3-b4156ee24717" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_c808c822-e537-44bb-8df3-b4156ee24717" xlink:type="arc" order="30"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentsIncorporatedByReferenceTextBlock_b0e9f191-a166-441c-a861-58f80d9390cd" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentsIncorporatedByReferenceTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_DocumentsIncorporatedByReferenceTextBlock_b0e9f191-a166-441c-a861-58f80d9390cd" xlink:type="arc" order="31"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_6096d5d2-6ebe-4c23-8adc-4124d4553940" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_AmendmentFlag_6096d5d2-6ebe-4c23-8adc-4124d4553940" xlink:type="arc" order="32"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_2b79efd0-ea3d-4fc1-b979-0b83f6d9521b" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_EntityCentralIndexKey_2b79efd0-ea3d-4fc1-b979-0b83f6d9521b" xlink:type="arc" order="33"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_7c3ccbe1-6706-4c39-9caf-004da4aeb53b" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_DocumentFiscalYearFocus_7c3ccbe1-6706-4c39-9caf-004da4aeb53b" xlink:type="arc" order="34"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_b5dcad66-4cb8-43d2-99fa-ee419c3d67cb" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityListingsLineItems_74244eed-2f17-4d3c-a282-34be474129bd" xlink:to="loc_dei_DocumentFiscalPeriodFocus_b5dcad66-4cb8-43d2-99fa-ee419c3d67cb" xlink:type="arc" order="35"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/ConsolidatedBalanceSheets" xlink:type="simple" xlink:href="cmpo-20231231.xsd#ConsolidatedBalanceSheets"/>
  <link:definitionLink xlink:role="http://composecure.com/role/ConsolidatedBalanceSheets" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_789a3e84-041e-4874-92a5-1a82a1a77678" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_cdbef26d-3915-4660-b063-b898166dd3e3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_789a3e84-041e-4874-92a5-1a82a1a77678" xlink:to="loc_us-gaap_StatementTable_cdbef26d-3915-4660-b063-b898166dd3e3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_a2737d77-c8b5-475f-ad94-47cc6fe01501" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_cdbef26d-3915-4660-b063-b898166dd3e3" xlink:to="loc_us-gaap_StatementClassOfStockAxis_a2737d77-c8b5-475f-ad94-47cc6fe01501" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_a2737d77-c8b5-475f-ad94-47cc6fe01501_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_a2737d77-c8b5-475f-ad94-47cc6fe01501" xlink:to="loc_us-gaap_ClassOfStockDomain_a2737d77-c8b5-475f-ad94-47cc6fe01501_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_e666feae-42f6-45f7-a22a-3a10677e1c81" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_a2737d77-c8b5-475f-ad94-47cc6fe01501" xlink:to="loc_us-gaap_ClassOfStockDomain_e666feae-42f6-45f7-a22a-3a10677e1c81" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_f14058a9-9ab8-4d99-8ef3-9d4286be366e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_e666feae-42f6-45f7-a22a-3a10677e1c81" xlink:to="loc_us-gaap_CommonClassAMember_f14058a9-9ab8-4d99-8ef3-9d4286be366e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_e1cdd4a1-721a-48a8-8ff4-5caa21704c83" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_e666feae-42f6-45f7-a22a-3a10677e1c81" xlink:to="loc_us-gaap_CommonClassBMember_e1cdd4a1-721a-48a8-8ff4-5caa21704c83" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_55a368b6-cbc8-4be5-8424-0d7ba9939dc6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_789a3e84-041e-4874-92a5-1a82a1a77678" xlink:to="loc_us-gaap_AssetsAbstract_55a368b6-cbc8-4be5-8424-0d7ba9939dc6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrentAbstract_f13c6208-fd38-421f-80c1-2612f8b41508" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_55a368b6-cbc8-4be5-8424-0d7ba9939dc6" xlink:to="loc_us-gaap_AssetsCurrentAbstract_f13c6208-fd38-421f-80c1-2612f8b41508" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_78881c38-d3ef-43c2-b956-7bfed94be60d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_f13c6208-fd38-421f-80c1-2612f8b41508" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_78881c38-d3ef-43c2-b956-7bfed94be60d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_8c705209-0234-4ccf-931d-f208cca31be7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_f13c6208-fd38-421f-80c1-2612f8b41508" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_8c705209-0234-4ccf-931d-f208cca31be7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet_3bd53f1c-8df5-4c71-8f6d-669c727c1bb7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_f13c6208-fd38-421f-80c1-2612f8b41508" xlink:to="loc_us-gaap_InventoryNet_3bd53f1c-8df5-4c71-8f6d-669c727c1bb7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_85755c32-9770-43ac-a71e-d75121115602" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_f13c6208-fd38-421f-80c1-2612f8b41508" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_85755c32-9770-43ac-a71e-d75121115602" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_e5d24199-e9a1-434b-ac15-4798ce85d719" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_f13c6208-fd38-421f-80c1-2612f8b41508" xlink:to="loc_us-gaap_AssetsCurrent_e5d24199-e9a1-434b-ac15-4798ce85d719" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_da1309df-8282-42e1-8072-3bfcb879f073" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_55a368b6-cbc8-4be5-8424-0d7ba9939dc6" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_da1309df-8282-42e1-8072-3bfcb879f073" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_faadd002-6f07-4409-86f9-896cde69714d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_55a368b6-cbc8-4be5-8424-0d7ba9939dc6" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_faadd002-6f07-4409-86f9-896cde69714d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxAssetsNet_6c18307c-be66-498b-a9f4-f287d7675b68" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredIncomeTaxAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_55a368b6-cbc8-4be5-8424-0d7ba9939dc6" xlink:to="loc_us-gaap_DeferredIncomeTaxAssetsNet_6c18307c-be66-498b-a9f4-f287d7675b68" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetsNoncurrent_e7b7725e-87c4-4f9c-8daa-0aab55306088" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_55a368b6-cbc8-4be5-8424-0d7ba9939dc6" xlink:to="loc_us-gaap_DerivativeAssetsNoncurrent_e7b7725e-87c4-4f9c-8daa-0aab55306088" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DepositsAndOtherAssetsNoncurrent_a919376b-ae51-4c41-998d-7705bb24216f" xlink:href="cmpo-20231231.xsd#cmpo_DepositsAndOtherAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_55a368b6-cbc8-4be5-8424-0d7ba9939dc6" xlink:to="loc_cmpo_DepositsAndOtherAssetsNoncurrent_a919376b-ae51-4c41-998d-7705bb24216f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_42a53086-6846-44db-8fa8-10614acaba87" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_55a368b6-cbc8-4be5-8424-0d7ba9939dc6" xlink:to="loc_us-gaap_Assets_42a53086-6846-44db-8fa8-10614acaba87" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_789a3e84-041e-4874-92a5-1a82a1a77678" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_b0540350-fd78-4b03-8596-76a87241c1f1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_b0540350-fd78-4b03-8596-76a87241c1f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_eb686c86-42ef-4c0c-be28-7fa1688c1a4f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b0540350-fd78-4b03-8596-76a87241c1f1" xlink:to="loc_us-gaap_LongTermDebtCurrent_eb686c86-42ef-4c0c-be28-7fa1688c1a4f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_71bddf9c-2b83-462a-895a-2cfac3ea0961" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b0540350-fd78-4b03-8596-76a87241c1f1" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_71bddf9c-2b83-462a-895a-2cfac3ea0961" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_TaxReceivableAgreementLiabilityCurrent_83c29938-ef77-4d21-9bc4-1618bee6f18b" xlink:href="cmpo-20231231.xsd#cmpo_TaxReceivableAgreementLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b0540350-fd78-4b03-8596-76a87241c1f1" xlink:to="loc_cmpo_TaxReceivableAgreementLiabilityCurrent_83c29938-ef77-4d21-9bc4-1618bee6f18b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent_dea6aa2c-28bb-409a-b75e-bcb6fa6157fb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsPayableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b0540350-fd78-4b03-8596-76a87241c1f1" xlink:to="loc_us-gaap_AccountsPayableCurrent_dea6aa2c-28bb-409a-b75e-bcb6fa6157fb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_913d6919-9206-4ac5-a7e5-f5799d1af336" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b0540350-fd78-4b03-8596-76a87241c1f1" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent_913d6919-9206-4ac5-a7e5-f5799d1af336" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_CommissionPayableCurrent_9568c6bb-a6a9-4d7a-843c-174f8613cdbf" xlink:href="cmpo-20231231.xsd#cmpo_CommissionPayableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b0540350-fd78-4b03-8596-76a87241c1f1" xlink:to="loc_cmpo_CommissionPayableCurrent_9568c6bb-a6a9-4d7a-843c-174f8613cdbf" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedBonusesCurrent_6202045a-7396-42f6-adb2-33ff93c1e1f2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccruedBonusesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b0540350-fd78-4b03-8596-76a87241c1f1" xlink:to="loc_us-gaap_AccruedBonusesCurrent_6202045a-7396-42f6-adb2-33ff93c1e1f2" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_80744620-6782-4fcc-aae5-0df2f9a8eede" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_b0540350-fd78-4b03-8596-76a87241c1f1" xlink:to="loc_us-gaap_LiabilitiesCurrent_80744620-6782-4fcc-aae5-0df2f9a8eede" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLongTermDebtNoncurrent_0241a4f2-b902-48ba-876b-e84c7e0c05a8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_us-gaap_OtherLongTermDebtNoncurrent_0241a4f2-b902-48ba-876b-e84c7e0c05a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleLongTermNotesPayable_16eeb607-0d54-46c9-a1c2-d8ffb0e810f5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConvertibleLongTermNotesPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_us-gaap_ConvertibleLongTermNotesPayable_16eeb607-0d54-46c9-a1c2-d8ffb0e810f5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability_c5582652-2e24-4693-91c2-34aa912ec23b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability_c5582652-2e24-4693-91c2-34aa912ec23b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstanding_440834d0-27bf-426b-b366-2a04b5bf4716" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WarrantsAndRightsOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_us-gaap_WarrantsAndRightsOutstanding_440834d0-27bf-426b-b366-2a04b5bf4716" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_b8e183fc-cbbd-46ca-866d-ecbe8b37db72" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_b8e183fc-cbbd-46ca-866d-ecbe8b37db72" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_TaxReceivableAgreementLiabilityNoncurrent_e645fb3c-0efd-4bb5-a618-8d7597e66e14" xlink:href="cmpo-20231231.xsd#cmpo_TaxReceivableAgreementLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_cmpo_TaxReceivableAgreementLiabilityNoncurrent_e645fb3c-0efd-4bb5-a618-8d7597e66e14" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DerivativeInstrumentContingentConsiderationLiability_d8532364-40b4-4195-bb18-5ea3259ef5d4" xlink:href="cmpo-20231231.xsd#cmpo_DerivativeInstrumentContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_cmpo_DerivativeInstrumentContingentConsiderationLiability_d8532364-40b4-4195-bb18-5ea3259ef5d4" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_f2dc5c43-856e-41ee-9043-f0674eb9ede8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_us-gaap_Liabilities_f2dc5c43-856e-41ee-9043-f0674eb9ede8" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_11eb2c6e-fb15-48c9-a129-45e8b723f981" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_us-gaap_CommitmentsAndContingencies_11eb2c6e-fb15-48c9-a129-45e8b723f981" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_27262a6c-4834-458c-89f8-223bc68ba560" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_27262a6c-4834-458c-89f8-223bc68ba560" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue_fa9fd99f-5216-477b-9cfe-0916d614f4fa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_us-gaap_PreferredStockValue_fa9fd99f-5216-477b-9cfe-0916d614f4fa" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_fec3f771-7e32-499e-96ec-0eee8a4e7831" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_us-gaap_CommonStockValue_fec3f771-7e32-499e-96ec-0eee8a4e7831" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital_ec7f0b5a-5531-46d5-a0fb-bf13f7486e99" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdditionalPaidInCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_us-gaap_AdditionalPaidInCapital_ec7f0b5a-5531-46d5-a0fb-bf13f7486e99" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_d8b93c59-fdff-43a4-9a8c-fd241a6ca571" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_d8b93c59-fdff-43a4-9a8c-fd241a6ca571" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_2154d271-fec6-45ca-a612-03cbe3006560" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_2154d271-fec6-45ca-a612-03cbe3006560" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_5482ae2b-2a12-451a-8068-fb9aea44b33c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_us-gaap_StockholdersEquity_5482ae2b-2a12-451a-8068-fb9aea44b33c" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_9804c855-954b-424b-ae87-3a36c5b967bd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ff51810c-673a-4040-8c62-4c43695054ce" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_9804c855-954b-424b-ae87-3a36c5b967bd" xlink:type="arc" order="18"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:type="simple" xlink:href="cmpo-20231231.xsd#ConsolidatedBalanceSheetsParenthetical"/>
  <link:definitionLink xlink:role="http://composecure.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_081a5907-7eca-47d1-948d-638f28190430" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_db8c8fe6-f6c1-474e-8960-f6d9162cd071" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_081a5907-7eca-47d1-948d-638f28190430" xlink:to="loc_us-gaap_StatementTable_db8c8fe6-f6c1-474e-8960-f6d9162cd071" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_566f2b39-1966-48c0-b080-1adcf7ff025d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_db8c8fe6-f6c1-474e-8960-f6d9162cd071" xlink:to="loc_us-gaap_StatementClassOfStockAxis_566f2b39-1966-48c0-b080-1adcf7ff025d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_566f2b39-1966-48c0-b080-1adcf7ff025d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_566f2b39-1966-48c0-b080-1adcf7ff025d" xlink:to="loc_us-gaap_ClassOfStockDomain_566f2b39-1966-48c0-b080-1adcf7ff025d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_cb0c03d0-0542-4701-8724-7b842b26d44a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_566f2b39-1966-48c0-b080-1adcf7ff025d" xlink:to="loc_us-gaap_ClassOfStockDomain_cb0c03d0-0542-4701-8724-7b842b26d44a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_1ed0faa9-4110-4c1e-a642-6cf944c19c5c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_cb0c03d0-0542-4701-8724-7b842b26d44a" xlink:to="loc_us-gaap_CommonClassAMember_1ed0faa9-4110-4c1e-a642-6cf944c19c5c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_2fbab2c2-96e1-4405-ab46-400b0c581ca1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_cb0c03d0-0542-4701-8724-7b842b26d44a" xlink:to="loc_us-gaap_CommonClassBMember_2fbab2c2-96e1-4405-ab46-400b0c581ca1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_32ff4be4-c8ff-42de-9261-865f6b6f953d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_081a5907-7eca-47d1-948d-638f28190430" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_32ff4be4-c8ff-42de-9261-865f6b6f953d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_ddf35f5a-3181-4780-aed4-ed7f76a487a5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_081a5907-7eca-47d1-948d-638f28190430" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_ddf35f5a-3181-4780-aed4-ed7f76a487a5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_d712c5f9-0f01-463e-9f9c-d4700740e1ad" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_081a5907-7eca-47d1-948d-638f28190430" xlink:to="loc_us-gaap_PreferredStockSharesIssued_d712c5f9-0f01-463e-9f9c-d4700740e1ad" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_101a6e66-05fa-40ec-b09e-dd554dfe0eae" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_081a5907-7eca-47d1-948d-638f28190430" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_101a6e66-05fa-40ec-b09e-dd554dfe0eae" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_e8fd4adc-45ac-486a-b8fb-3a56de34d305" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_081a5907-7eca-47d1-948d-638f28190430" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_e8fd4adc-45ac-486a-b8fb-3a56de34d305" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_169982a7-8d33-484c-b0b9-68392b7345d6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_081a5907-7eca-47d1-948d-638f28190430" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_169982a7-8d33-484c-b0b9-68392b7345d6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_cabdc579-a7b7-4396-b844-3de0790c697b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_081a5907-7eca-47d1-948d-638f28190430" xlink:to="loc_us-gaap_CommonStockSharesIssued_cabdc579-a7b7-4396-b844-3de0790c697b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_c66cc0e9-116f-4138-af80-4eb044f035b4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_081a5907-7eca-47d1-948d-638f28190430" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_c66cc0e9-116f-4138-af80-4eb044f035b4" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/ConsolidatedStatementsofStockholdersEquity" xlink:type="simple" xlink:href="cmpo-20231231.xsd#ConsolidatedStatementsofStockholdersEquity"/>
  <link:definitionLink xlink:role="http://composecure.com/role/ConsolidatedStatementsofStockholdersEquity" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_978d043d-6ae3-45a8-9dc0-5f578063f78a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_40ed741b-2cdc-4c09-9dcb-170299a2e6b0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_978d043d-6ae3-45a8-9dc0-5f578063f78a" xlink:to="loc_us-gaap_StatementTable_40ed741b-2cdc-4c09-9dcb-170299a2e6b0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_5a4edb58-2034-465a-a1b4-69541f6440ee" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_40ed741b-2cdc-4c09-9dcb-170299a2e6b0" xlink:to="loc_us-gaap_StatementClassOfStockAxis_5a4edb58-2034-465a-a1b4-69541f6440ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_5a4edb58-2034-465a-a1b4-69541f6440ee_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_5a4edb58-2034-465a-a1b4-69541f6440ee" xlink:to="loc_us-gaap_ClassOfStockDomain_5a4edb58-2034-465a-a1b4-69541f6440ee_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_2e101846-9c84-40e0-9ed7-95c694eeb4ad" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_5a4edb58-2034-465a-a1b4-69541f6440ee" xlink:to="loc_us-gaap_ClassOfStockDomain_2e101846-9c84-40e0-9ed7-95c694eeb4ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_cbd848db-1d30-4758-9c17-c588b9516d94" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_2e101846-9c84-40e0-9ed7-95c694eeb4ad" xlink:to="loc_us-gaap_CommonClassAMember_cbd848db-1d30-4758-9c17-c588b9516d94" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_ee0b4cc7-74c9-4d48-9bd9-b2aaf475d4de" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_2e101846-9c84-40e0-9ed7-95c694eeb4ad" xlink:to="loc_us-gaap_CommonClassBMember_ee0b4cc7-74c9-4d48-9bd9-b2aaf475d4de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_a977aef5-9ab6-4112-b945-7468df6b6992" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_40ed741b-2cdc-4c09-9dcb-170299a2e6b0" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_a977aef5-9ab6-4112-b945-7468df6b6992" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_a977aef5-9ab6-4112-b945-7468df6b6992_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_a977aef5-9ab6-4112-b945-7468df6b6992" xlink:to="loc_us-gaap_EquityComponentDomain_a977aef5-9ab6-4112-b945-7468df6b6992_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_7f0e01a3-8825-45fe-b52c-aafb2624eec3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_a977aef5-9ab6-4112-b945-7468df6b6992" xlink:to="loc_us-gaap_EquityComponentDomain_7f0e01a3-8825-45fe-b52c-aafb2624eec3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_e9fb29c7-8c4b-4529-9f38-330fe3b9acbb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_7f0e01a3-8825-45fe-b52c-aafb2624eec3" xlink:to="loc_us-gaap_CommonStockMember_e9fb29c7-8c4b-4529-9f38-330fe3b9acbb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_8e030d38-8638-4b5b-8dcc-02ee8b9dee17" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_7f0e01a3-8825-45fe-b52c-aafb2624eec3" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_8e030d38-8638-4b5b-8dcc-02ee8b9dee17" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_21f5e803-1e48-461f-b018-6b706077a8f0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_7f0e01a3-8825-45fe-b52c-aafb2624eec3" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_21f5e803-1e48-461f-b018-6b706077a8f0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_4f5f40f8-26d6-4e07-b462-510331436d90" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_7f0e01a3-8825-45fe-b52c-aafb2624eec3" xlink:to="loc_us-gaap_RetainedEarningsMember_4f5f40f8-26d6-4e07-b462-510331436d90" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_978d043d-6ae3-45a8-9dc0-5f578063f78a" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_e0696fa3-c70e-4283-9766-1d0b9704a908" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:to="loc_us-gaap_SharesOutstanding_e0696fa3-c70e-4283-9766-1d0b9704a908" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_8d212afa-dff2-44fb-8b30-2f3e57eb5d99" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:to="loc_us-gaap_StockholdersEquity_8d212afa-dff2-44fb-8b30-2f3e57eb5d99" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Dividends_99d3f162-3899-4267-8c9b-d0dcce831be7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Dividends"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:to="loc_us-gaap_Dividends_99d3f162-3899-4267-8c9b-d0dcce831be7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_690758ad-892b-4dd6-93ea-cfaec8f3a00c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_690758ad-892b-4dd6-93ea-cfaec8f3a00c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_95a7b85f-14fb-470a-84fd-25fae8ecf0d6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_95a7b85f-14fb-470a-84fd-25fae8ecf0d6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_c763dce7-b1ad-49f6-8db5-0d106abced51" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_c763dce7-b1ad-49f6-8db5-0d106abced51" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts_7bc323a8-06c1-456c-ba2e-1f038b5b7e5d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts_7bc323a8-06c1-456c-ba2e-1f038b5b7e5d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_ee9a481d-90fb-4f61-8e93-5d44c2eda395" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:to="loc_us-gaap_NetIncomeLoss_ee9a481d-90fb-4f61-8e93-5d44c2eda395" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_54bb31d7-8b25-4ef1-8a0c-e023f5bb150a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_54bb31d7-8b25-4ef1-8a0c-e023f5bb150a" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromStockOptionsExercised_0a4686d2-168d-4197-ab4f-84db69bc12b4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:to="loc_us-gaap_ProceedsFromStockOptionsExercised_0a4686d2-168d-4197-ab4f-84db69bc12b4" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_5362070b-41e9-4d1a-9f1c-e29782d0428c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:to="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_5362070b-41e9-4d1a-9f1c-e29782d0428c" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_4b50d1f6-674f-4c0b-9182-085b865e40d7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_4b50d1f6-674f-4c0b-9182-085b865e40d7" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_e79f81d0-27ff-4f58-bf7d-17baf795d7a9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_e79f81d0-27ff-4f58-bf7d-17baf795d7a9" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_436b356f-c1e9-43c7-ace8-b6220baf7c02" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_436b356f-c1e9-43c7-ace8-b6220baf7c02" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_462fbf86-2ff9-49e8-845b-2b24cf6f3d47" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_462fbf86-2ff9-49e8-845b-2b24cf6f3d47" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_AdjustmentsToPaidInCapitalTaxReceivableAgreementLiability_dbd4f0e4-9612-430c-96f2-6433b993faee" xlink:href="cmpo-20231231.xsd#cmpo_AdjustmentsToPaidInCapitalTaxReceivableAgreementLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:to="loc_cmpo_AdjustmentsToPaidInCapitalTaxReceivableAgreementLiability_dbd4f0e4-9612-430c-96f2-6433b993faee" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestChangeInRedemptionValue_10c69bf0-1eb7-4980-9627-9a029d5ba60a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MinorityInterestChangeInRedemptionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_25103d52-7930-421a-9a5b-feb59364581c" xlink:to="loc_us-gaap_MinorityInterestChangeInRedemptionValue_10c69bf0-1eb7-4980-9627-9a029d5ba60a" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_1d6141df-6da5-489e-a4a5-a8c09d940c04" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_a38fb5ea-14d4-4f8b-b518-7ebfb93f72e4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_9a2c671f-1024-413a-9e47-d9804d5793c8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInTemporaryEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_978d043d-6ae3-45a8-9dc0-5f578063f78a" xlink:to="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_9a2c671f-1024-413a-9e47-d9804d5793c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_2bbabb43-3736-447a-b9f1-28d2aded06e4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_9a2c671f-1024-413a-9e47-d9804d5793c8" xlink:to="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_2bbabb43-3736-447a-b9f1-28d2aded06e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest_808cda5e-4f09-440d-a78f-2cd5906936dc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_9a2c671f-1024-413a-9e47-d9804d5793c8" xlink:to="loc_us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest_808cda5e-4f09-440d-a78f-2cd5906936dc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_380fe630-13e1-445c-80a0-5edcd792ad0e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_9a2c671f-1024-413a-9e47-d9804d5793c8" xlink:to="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_380fe630-13e1-445c-80a0-5edcd792ad0e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityAccretionToRedemptionValueAdjustment_77e7ed3c-74a0-4179-b6e6-7eec8717e909" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquityAccretionToRedemptionValueAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_9a2c671f-1024-413a-9e47-d9804d5793c8" xlink:to="loc_us-gaap_TemporaryEquityAccretionToRedemptionValueAdjustment_77e7ed3c-74a0-4179-b6e6-7eec8717e909" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_dc450d43-2383-4c5b-9a22-be9769372c8b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfIncentiveDistributionMadeToManagingMemberOrGeneralPartnerTable_0f7f7eeb-c9cb-4e93-8624-e70caeee64df" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfIncentiveDistributionMadeToManagingMemberOrGeneralPartnerTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_us-gaap_ScheduleOfIncentiveDistributionMadeToManagingMemberOrGeneralPartnerTable_0f7f7eeb-c9cb-4e93-8624-e70caeee64df" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_a06c3271-fa28-4d0f-85dc-6ade41cdce0b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfIncentiveDistributionMadeToManagingMemberOrGeneralPartnerTable_0f7f7eeb-c9cb-4e93-8624-e70caeee64df" xlink:to="loc_srt_RangeAxis_a06c3271-fa28-4d0f-85dc-6ade41cdce0b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_a06c3271-fa28-4d0f-85dc-6ade41cdce0b_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_a06c3271-fa28-4d0f-85dc-6ade41cdce0b" xlink:to="loc_srt_RangeMember_a06c3271-fa28-4d0f-85dc-6ade41cdce0b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_963b6100-cd98-4322-91ef-d00d71d2bb22" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_a06c3271-fa28-4d0f-85dc-6ade41cdce0b" xlink:to="loc_srt_RangeMember_963b6100-cd98-4322-91ef-d00d71d2bb22" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_fbf45aba-0543-4a51-9f32-678e5ebfd840" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_963b6100-cd98-4322-91ef-d00d71d2bb22" xlink:to="loc_srt_MinimumMember_fbf45aba-0543-4a51-9f32-678e5ebfd840" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_3b7812cf-09ce-4df5-8c46-c7adf6e38ca1" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_963b6100-cd98-4322-91ef-d00d71d2bb22" xlink:to="loc_srt_MaximumMember_3b7812cf-09ce-4df5-8c46-c7adf6e38ca1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_c3c59d3c-3ca2-434a-b74a-c01ad424a6b9" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfIncentiveDistributionMadeToManagingMemberOrGeneralPartnerTable_0f7f7eeb-c9cb-4e93-8624-e70caeee64df" xlink:to="loc_srt_ConsolidatedEntitiesAxis_c3c59d3c-3ca2-434a-b74a-c01ad424a6b9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_c3c59d3c-3ca2-434a-b74a-c01ad424a6b9_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_c3c59d3c-3ca2-434a-b74a-c01ad424a6b9" xlink:to="loc_srt_ConsolidatedEntitiesDomain_c3c59d3c-3ca2-434a-b74a-c01ad424a6b9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_11fe813c-b363-47ce-9848-746ed3075641" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_c3c59d3c-3ca2-434a-b74a-c01ad424a6b9" xlink:to="loc_srt_ConsolidatedEntitiesDomain_11fe813c-b363-47ce-9848-746ed3075641" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ParentCompanyMember_6e40f8bc-18fb-46ab-8275-5b530a9b265e" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ParentCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_11fe813c-b363-47ce-9848-746ed3075641" xlink:to="loc_srt_ParentCompanyMember_6e40f8bc-18fb-46ab-8275-5b530a9b265e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AffiliatedEntityMember_813612b8-a044-40ba-a3f8-aabbca0cea5c" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_AffiliatedEntityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_11fe813c-b363-47ce-9848-746ed3075641" xlink:to="loc_srt_AffiliatedEntityMember_813612b8-a044-40ba-a3f8-aabbca0cea5c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_95e45f46-995e-4902-9298-044630dfc381" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_95e45f46-995e-4902-9298-044630dfc381" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_2e7084fa-6ece-491f-a34f-0f630c6e88b7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_2e7084fa-6ece-491f-a34f-0f630c6e88b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetNet_ecf7eb3a-4e7e-4528-b45d-2d3fd8692cf2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerAssetNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_us-gaap_ContractWithCustomerAssetNet_ecf7eb3a-4e7e-4528-b45d-2d3fd8692cf2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiability_4aa37429-e99f-48b8-bd9b-cc0b419dc572" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_us-gaap_ContractWithCustomerLiability_4aa37429-e99f-48b8-bd9b-cc0b419dc572" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_RevenuePerformanceObligationPaymentTermsMinimum_714eb461-ee74-4afc-92cc-358364f4ac9c" xlink:href="cmpo-20231231.xsd#cmpo_RevenuePerformanceObligationPaymentTermsMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_cmpo_RevenuePerformanceObligationPaymentTermsMinimum_714eb461-ee74-4afc-92cc-358364f4ac9c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_RevenuePerformanceObligationPaymentTermsMaximum_d632f6c7-4ed5-472f-9935-9d7bd78ab460" xlink:href="cmpo-20231231.xsd#cmpo_RevenuePerformanceObligationPaymentTermsMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_cmpo_RevenuePerformanceObligationPaymentTermsMaximum_d632f6c7-4ed5-472f-9935-9d7bd78ab460" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_RevenuePerformanceObligationPaymentDue_7bcaeb75-4fe8-437b-a6af-47156976f497" xlink:href="cmpo-20231231.xsd#cmpo_RevenuePerformanceObligationPaymentDue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_cmpo_RevenuePerformanceObligationPaymentDue_7bcaeb75-4fe8-437b-a6af-47156976f497" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ShippingAndHandlingCosts_9382e3ca-1d14-41ec-8ddd-09a78376b6b3" xlink:href="cmpo-20231231.xsd#cmpo_ShippingAndHandlingCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_cmpo_ShippingAndHandlingCosts_9382e3ca-1d14-41ec-8ddd-09a78376b6b3" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_c7204ac2-1c73-4d45-bde4-f049e37a7e49" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_c7204ac2-1c73-4d45-bde4-f049e37a7e49" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingExpense_1f3c56a5-ecd7-45e9-b2c6-1afd4bfd1d32" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SellingExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_us-gaap_SellingExpense_1f3c56a5-ecd7-45e9-b2c6-1afd4bfd1d32" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTaxExpenseDueFromAffiliatesCurrent_49c0a72d-3ff0-4b90-90fb-e5d96c3c6fd0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTaxExpenseDueFromAffiliatesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_us-gaap_RelatedPartyTaxExpenseDueFromAffiliatesCurrent_49c0a72d-3ff0-4b90-90fb-e5d96c3c6fd0" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DerivativeInstrumentContingentConsiderationLiabilityShares_1ea3eb29-f659-48da-b68b-9ab61be02da8" xlink:href="cmpo-20231231.xsd#cmpo_DerivativeInstrumentContingentConsiderationLiabilityShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_cmpo_DerivativeInstrumentContingentConsiderationLiabilityShares_1ea3eb29-f659-48da-b68b-9ab61be02da8" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DerivativeInstrumentContingentConsiderationNumberOfPhases_613630b5-b8ea-4707-96fa-d08ea7fa4ed9" xlink:href="cmpo-20231231.xsd#cmpo_DerivativeInstrumentContingentConsiderationNumberOfPhases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_cmpo_DerivativeInstrumentContingentConsiderationNumberOfPhases_613630b5-b8ea-4707-96fa-d08ea7fa4ed9" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DerivativeInstrumentContingentConsiderationExpirationPeriodInitialPhase_b9068e17-08a6-48db-8c5f-cc2bbf7cfb7e" xlink:href="cmpo-20231231.xsd#cmpo_DerivativeInstrumentContingentConsiderationExpirationPeriodInitialPhase"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_cmpo_DerivativeInstrumentContingentConsiderationExpirationPeriodInitialPhase_b9068e17-08a6-48db-8c5f-cc2bbf7cfb7e" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DerivativeInstrumentContingentConsiderationExpirationPeriodSecondPhase_bb806f63-1d85-4bbf-aa44-cdc7050bf999" xlink:href="cmpo-20231231.xsd#cmpo_DerivativeInstrumentContingentConsiderationExpirationPeriodSecondPhase"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_cmpo_DerivativeInstrumentContingentConsiderationExpirationPeriodSecondPhase_bb806f63-1d85-4bbf-aa44-cdc7050bf999" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_TaxReceivableAgreementPercentage_74f62d37-2625-4d7e-8bc1-37e8e6ff7147" xlink:href="cmpo-20231231.xsd#cmpo_TaxReceivableAgreementPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_cmpo_TaxReceivableAgreementPercentage_74f62d37-2625-4d7e-8bc1-37e8e6ff7147" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_TaxReceivableAgreementPercentageRetained_4317dab9-f7fe-4b86-9af4-823b9405f947" xlink:href="cmpo-20231231.xsd#cmpo_TaxReceivableAgreementPercentageRetained"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_cmpo_TaxReceivableAgreementPercentageRetained_4317dab9-f7fe-4b86-9af4-823b9405f947" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_TaxReceivableAgreementLiability_96a91aeb-cbc9-4910-b9cd-a16e1ba9f18a" xlink:href="cmpo-20231231.xsd#cmpo_TaxReceivableAgreementLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_cmpo_TaxReceivableAgreementLiability_96a91aeb-cbc9-4910-b9cd-a16e1ba9f18a" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_PaymentOnTaxReceivableAgreementLiability_31dc4cb7-abda-4fb3-b2c9-0a63f2127734" xlink:href="cmpo-20231231.xsd#cmpo_PaymentOnTaxReceivableAgreementLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_cmpo_PaymentOnTaxReceivableAgreementLiability_31dc4cb7-abda-4fb3-b2c9-0a63f2127734" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_SalariesAndCommissions_3f98ca69-c33d-484f-a088-8a0c64ba5866" xlink:href="cmpo-20231231.xsd#cmpo_SalariesAndCommissions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_cmpo_SalariesAndCommissions_3f98ca69-c33d-484f-a088-8a0c64ba5866" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfessionalFees_a027088a-e4bd-4f72-8692-cf3acd75fec2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProfessionalFees"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_us-gaap_ProfessionalFees_a027088a-e4bd-4f72-8692-cf3acd75fec2" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtFairValueDisclosures_9918576d-e37d-42aa-a533-c297c3b5ced2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConvertibleDebtFairValueDisclosures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_us-gaap_ConvertibleDebtFairValueDisclosures_9918576d-e37d-42aa-a533-c297c3b5ced2" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfOperatingSegments_02e08bde-e6ad-45bb-a057-0f4011e16bfb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NumberOfOperatingSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_us-gaap_NumberOfOperatingSegments_02e08bde-e6ad-45bb-a057-0f4011e16bfb" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_35fb3cf4-3c59-434c-8ca3-0fce1b7b0feb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncentiveDistributionMadeToManagingMemberOrGeneralPartnerLineItems_482ea27b-8511-4612-80ae-4ff6bedaecab" xlink:to="loc_us-gaap_NumberOfReportableSegments_35fb3cf4-3c59-434c-8ca3-0fce1b7b0feb" xlink:type="arc" order="23"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/BUSINESSCOMBINATIONNarrativeDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#BUSINESSCOMBINATIONNarrativeDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/BUSINESSCOMBINATIONNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ReverseRecapitalizationLineItems_d7ffef04-0623-4985-a14d-85101785a576" xlink:href="cmpo-20231231.xsd#cmpo_ReverseRecapitalizationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ReverseRecapitalizationTable_b782fd38-0e02-4946-9a02-42c229d8d409" xlink:href="cmpo-20231231.xsd#cmpo_ReverseRecapitalizationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_d7ffef04-0623-4985-a14d-85101785a576" xlink:to="loc_cmpo_ReverseRecapitalizationTable_b782fd38-0e02-4946-9a02-42c229d8d409" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_3180d1a2-0be8-400a-8a86-fd8c49b09ce6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_cmpo_ReverseRecapitalizationTable_b782fd38-0e02-4946-9a02-42c229d8d409" xlink:to="loc_us-gaap_StatementClassOfStockAxis_3180d1a2-0be8-400a-8a86-fd8c49b09ce6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_3180d1a2-0be8-400a-8a86-fd8c49b09ce6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_3180d1a2-0be8-400a-8a86-fd8c49b09ce6" xlink:to="loc_us-gaap_ClassOfStockDomain_3180d1a2-0be8-400a-8a86-fd8c49b09ce6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_5859796e-4291-4880-864c-ee1a953a77dd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_3180d1a2-0be8-400a-8a86-fd8c49b09ce6" xlink:to="loc_us-gaap_ClassOfStockDomain_5859796e-4291-4880-864c-ee1a953a77dd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_993d9d7a-6b97-4361-8547-7eeef27dbd38" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_5859796e-4291-4880-864c-ee1a953a77dd" xlink:to="loc_us-gaap_CommonClassBMember_993d9d7a-6b97-4361-8547-7eeef27dbd38" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_CommonStockVotingRightsNumberOfVotes_840b7b8d-b650-486a-9209-bb586588e916" xlink:href="cmpo-20231231.xsd#cmpo_CommonStockVotingRightsNumberOfVotes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_d7ffef04-0623-4985-a14d-85101785a576" xlink:to="loc_cmpo_CommonStockVotingRightsNumberOfVotes_840b7b8d-b650-486a-9209-bb586588e916" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_RecapitalizationExchangeRatio_16075c9a-0f2b-41a4-bbb6-63e48046e2b9" xlink:href="cmpo-20231231.xsd#cmpo_RecapitalizationExchangeRatio"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_d7ffef04-0623-4985-a14d-85101785a576" xlink:to="loc_cmpo_RecapitalizationExchangeRatio_16075c9a-0f2b-41a4-bbb6-63e48046e2b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DerivativeInstrumentContingentConsiderationLiabilityShares_0ddfb7e5-73c3-4e0f-9e9f-e7e24e60bdbe" xlink:href="cmpo-20231231.xsd#cmpo_DerivativeInstrumentContingentConsiderationLiabilityShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_d7ffef04-0623-4985-a14d-85101785a576" xlink:to="loc_cmpo_DerivativeInstrumentContingentConsiderationLiabilityShares_0ddfb7e5-73c3-4e0f-9e9f-e7e24e60bdbe" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_TaxReceivableAgreementPercentage_9979e56c-01f6-4ed4-bf3b-82a22e7af1b6" xlink:href="cmpo-20231231.xsd#cmpo_TaxReceivableAgreementPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_d7ffef04-0623-4985-a14d-85101785a576" xlink:to="loc_cmpo_TaxReceivableAgreementPercentage_9979e56c-01f6-4ed4-bf3b-82a22e7af1b6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_9caaa627-5d1c-4a72-852f-a9979d0d61de" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_d7ffef04-0623-4985-a14d-85101785a576" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_9caaa627-5d1c-4a72-852f-a9979d0d61de" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_61135f0c-55ff-4303-a44d-dd40688fc76d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockPricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_d7ffef04-0623-4985-a14d-85101785a576" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_61135f0c-55ff-4303-a44d-dd40688fc76d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_2e4b6a03-354c-4500-9062-fe63394bc1c2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_d7ffef04-0623-4985-a14d-85101785a576" xlink:to="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_2e4b6a03-354c-4500-9062-fe63394bc1c2" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/BUSINESSCOMBINATIONRecapitalizationDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#BUSINESSCOMBINATIONRecapitalizationDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/BUSINESSCOMBINATIONRecapitalizationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ReverseRecapitalizationLineItems_e0a17628-d801-40b4-9f21-33f7fc958c1c" xlink:href="cmpo-20231231.xsd#cmpo_ReverseRecapitalizationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ReverseRecapitalizationTable_15cd0816-4193-45e8-9f2b-581bfbe20597" xlink:href="cmpo-20231231.xsd#cmpo_ReverseRecapitalizationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_e0a17628-d801-40b4-9f21-33f7fc958c1c" xlink:to="loc_cmpo_ReverseRecapitalizationTable_15cd0816-4193-45e8-9f2b-581bfbe20597" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_a0bcd7d3-c2fb-483e-b127-b591dacc4e57" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_cmpo_ReverseRecapitalizationTable_15cd0816-4193-45e8-9f2b-581bfbe20597" xlink:to="loc_us-gaap_StatementClassOfStockAxis_a0bcd7d3-c2fb-483e-b127-b591dacc4e57" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_a0bcd7d3-c2fb-483e-b127-b591dacc4e57_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_a0bcd7d3-c2fb-483e-b127-b591dacc4e57" xlink:to="loc_us-gaap_ClassOfStockDomain_a0bcd7d3-c2fb-483e-b127-b591dacc4e57_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_848fa831-8a91-400c-943a-cba0e1281de5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_a0bcd7d3-c2fb-483e-b127-b591dacc4e57" xlink:to="loc_us-gaap_ClassOfStockDomain_848fa831-8a91-400c-943a-cba0e1281de5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_51f22d8b-235b-4b88-b954-cd6d52b1a103" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_848fa831-8a91-400c-943a-cba0e1281de5" xlink:to="loc_us-gaap_CommonStockMember_51f22d8b-235b-4b88-b954-cd6d52b1a103" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ExchangeableNotesMember_f58d41e3-f8d7-4f90-bad3-e137a3fdf72c" xlink:href="cmpo-20231231.xsd#cmpo_ExchangeableNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_848fa831-8a91-400c-943a-cba0e1281de5" xlink:to="loc_cmpo_ExchangeableNotesMember_f58d41e3-f8d7-4f90-bad3-e137a3fdf72c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_CashAcquiredThroughReverseRecapitalization_e49d230e-40c1-4ffc-ba96-89b6e71a4a67" xlink:href="cmpo-20231231.xsd#cmpo_CashAcquiredThroughReverseRecapitalization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_e0a17628-d801-40b4-9f21-33f7fc958c1c" xlink:to="loc_cmpo_CashAcquiredThroughReverseRecapitalization_e49d230e-40c1-4ffc-ba96-89b6e71a4a67" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfPrivatePlacement_e3dc232b-7661-4cce-a4ec-c48bd474a98d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromIssuanceOfPrivatePlacement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_e0a17628-d801-40b4-9f21-33f7fc958c1c" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfPrivatePlacement_e3dc232b-7661-4cce-a4ec-c48bd474a98d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_PaymentsOfReverseRecapitalizationTransactionCosts_57e6385e-049e-452c-9929-46535b15e568" xlink:href="cmpo-20231231.xsd#cmpo_PaymentsOfReverseRecapitalizationTransactionCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_e0a17628-d801-40b4-9f21-33f7fc958c1c" xlink:to="loc_cmpo_PaymentsOfReverseRecapitalizationTransactionCosts_57e6385e-049e-452c-9929-46535b15e568" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ProceedsFromReverseRecapitalizationTransaction_3471ca9b-ef3a-49fb-8b34-04ddb67dc65f" xlink:href="cmpo-20231231.xsd#cmpo_ProceedsFromReverseRecapitalizationTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_e0a17628-d801-40b4-9f21-33f7fc958c1c" xlink:to="loc_cmpo_ProceedsFromReverseRecapitalizationTransaction_3471ca9b-ef3a-49fb-8b34-04ddb67dc65f" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/BUSINESSCOMBINATIONCommonStockDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#BUSINESSCOMBINATIONCommonStockDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/BUSINESSCOMBINATIONCommonStockDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ReverseRecapitalizationLineItems_bb54bd62-ac86-4406-ad8a-3cefbb6ade82" xlink:href="cmpo-20231231.xsd#cmpo_ReverseRecapitalizationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ReverseRecapitalizationTable_9937f197-025a-4444-b478-5093f37f8ecf" xlink:href="cmpo-20231231.xsd#cmpo_ReverseRecapitalizationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_bb54bd62-ac86-4406-ad8a-3cefbb6ade82" xlink:to="loc_cmpo_ReverseRecapitalizationTable_9937f197-025a-4444-b478-5093f37f8ecf" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_e1176f02-f2b2-42f1-8804-868e398187d8" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_cmpo_ReverseRecapitalizationTable_9937f197-025a-4444-b478-5093f37f8ecf" xlink:to="loc_dei_LegalEntityAxis_e1176f02-f2b2-42f1-8804-868e398187d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_e1176f02-f2b2-42f1-8804-868e398187d8_default" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_e1176f02-f2b2-42f1-8804-868e398187d8" xlink:to="loc_dei_EntityDomain_e1176f02-f2b2-42f1-8804-868e398187d8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_fb04be6a-b5dc-4355-b55f-d5998766c82b" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_e1176f02-f2b2-42f1-8804-868e398187d8" xlink:to="loc_dei_EntityDomain_fb04be6a-b5dc-4355-b55f-d5998766c82b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_RomanDBDRMember_9b4680fc-197c-4241-a183-5244a5031a55" xlink:href="cmpo-20231231.xsd#cmpo_RomanDBDRMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_fb04be6a-b5dc-4355-b55f-d5998766c82b" xlink:to="loc_cmpo_RomanDBDRMember_9b4680fc-197c-4241-a183-5244a5031a55" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_b7175a7a-e102-46e6-86d7-032a893aa73a" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_cmpo_ReverseRecapitalizationTable_9937f197-025a-4444-b478-5093f37f8ecf" xlink:to="loc_srt_CounterpartyNameAxis_b7175a7a-e102-46e6-86d7-032a893aa73a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_b7175a7a-e102-46e6-86d7-032a893aa73a_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_b7175a7a-e102-46e6-86d7-032a893aa73a" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_b7175a7a-e102-46e6-86d7-032a893aa73a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_ac812861-5a14-4f9b-8848-cbb24969c922" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_b7175a7a-e102-46e6-86d7-032a893aa73a" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_ac812861-5a14-4f9b-8848-cbb24969c922" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_CommonShareholdersMember_70569c7a-659b-41c6-83f2-f69da53446e0" xlink:href="cmpo-20231231.xsd#cmpo_CommonShareholdersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_ac812861-5a14-4f9b-8848-cbb24969c922" xlink:to="loc_cmpo_CommonShareholdersMember_70569c7a-659b-41c6-83f2-f69da53446e0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_RomanDBDRFoundersMember_5ca7459d-3369-4ad4-b176-3e3aa7679b42" xlink:href="cmpo-20231231.xsd#cmpo_RomanDBDRFoundersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_ac812861-5a14-4f9b-8848-cbb24969c922" xlink:to="loc_cmpo_RomanDBDRFoundersMember_5ca7459d-3369-4ad4-b176-3e3aa7679b42" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_cb55d718-9cc7-4c44-b27c-3342fd95379a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_bb54bd62-ac86-4406-ad8a-3cefbb6ade82" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_cb55d718-9cc7-4c44-b27c-3342fd95379a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_a92dcd29-ebef-4c11-b907-744ced1edb71" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockRepurchasedDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_bb54bd62-ac86-4406-ad8a-3cefbb6ade82" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_a92dcd29-ebef-4c11-b907-744ced1edb71" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions_a933ec81-8a9d-4a92-8454-ef20734aed78" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesAcquisitions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_bb54bd62-ac86-4406-ad8a-3cefbb6ade82" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions_a933ec81-8a9d-4a92-8454-ef20734aed78" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_621874c7-f698-4ca8-8b2b-6828bc219e37" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_bb54bd62-ac86-4406-ad8a-3cefbb6ade82" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_621874c7-f698-4ca8-8b2b-6828bc219e37" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_StockIssuedDuringPeriodSharesReverseRecapitalization_d71b5530-4886-4a1b-b287-42e60e06ec38" xlink:href="cmpo-20231231.xsd#cmpo_StockIssuedDuringPeriodSharesReverseRecapitalization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_bb54bd62-ac86-4406-ad8a-3cefbb6ade82" xlink:to="loc_cmpo_StockIssuedDuringPeriodSharesReverseRecapitalization_d71b5530-4886-4a1b-b287-42e60e06ec38" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_StockConvertedReverseRecapitalization_db6dd9ef-1086-4d7e-af80-e4012b554b91" xlink:href="cmpo-20231231.xsd#cmpo_StockConvertedReverseRecapitalization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_ReverseRecapitalizationLineItems_bb54bd62-ac86-4406-ad8a-3cefbb6ade82" xlink:to="loc_cmpo_StockConvertedReverseRecapitalization_db6dd9ef-1086-4d7e-af80-e4012b554b91" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/REVENUERECOGNITIONDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#REVENUERECOGNITIONDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/REVENUERECOGNITIONDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskLineItems_1b46a670-4e18-4904-93de-6ce4b14cdb20" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTable_d441222d-d0a1-4e30-96ec-0863513cde50" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_1b46a670-4e18-4904-93de-6ce4b14cdb20" xlink:to="loc_us-gaap_ConcentrationRiskTable_d441222d-d0a1-4e30-96ec-0863513cde50" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_3940a046-1043-4535-9ebc-22483554145f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_d441222d-d0a1-4e30-96ec-0863513cde50" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_3940a046-1043-4535-9ebc-22483554145f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_3940a046-1043-4535-9ebc-22483554145f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_3940a046-1043-4535-9ebc-22483554145f" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_3940a046-1043-4535-9ebc-22483554145f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_37fce310-7b62-4a60-a92f-bd915e5a9f79" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_3940a046-1043-4535-9ebc-22483554145f" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_37fce310-7b62-4a60-a92f-bd915e5a9f79" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_9be9f07d-0f23-401d-a7fd-65e0551946d1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_37fce310-7b62-4a60-a92f-bd915e5a9f79" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_9be9f07d-0f23-401d-a7fd-65e0551946d1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_1af71328-28ce-40d5-bed0-1432292f73fc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_d441222d-d0a1-4e30-96ec-0863513cde50" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_1af71328-28ce-40d5-bed0-1432292f73fc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_1af71328-28ce-40d5-bed0-1432292f73fc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_1af71328-28ce-40d5-bed0-1432292f73fc" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_1af71328-28ce-40d5-bed0-1432292f73fc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_971f0d73-699e-495b-802e-3935526ec44f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_1af71328-28ce-40d5-bed0-1432292f73fc" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_971f0d73-699e-495b-802e-3935526ec44f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_f722e59d-bfdd-48ab-85a3-bc93b3c35b49" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_971f0d73-699e-495b-802e-3935526ec44f" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_f722e59d-bfdd-48ab-85a3-bc93b3c35b49" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_f296bdc4-12c7-42ad-afd5-5f0ffc1af98f" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_d441222d-d0a1-4e30-96ec-0863513cde50" xlink:to="loc_srt_MajorCustomersAxis_f296bdc4-12c7-42ad-afd5-5f0ffc1af98f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_f296bdc4-12c7-42ad-afd5-5f0ffc1af98f_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_f296bdc4-12c7-42ad-afd5-5f0ffc1af98f" xlink:to="loc_srt_NameOfMajorCustomerDomain_f296bdc4-12c7-42ad-afd5-5f0ffc1af98f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_ea5e626e-b945-441b-b464-7fdd07d80f84" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_f296bdc4-12c7-42ad-afd5-5f0ffc1af98f" xlink:to="loc_srt_NameOfMajorCustomerDomain_ea5e626e-b945-441b-b464-7fdd07d80f84" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_TopTwoCustomersMember_dcb3153c-0aa6-4d95-99f1-c8ac9dd03881" xlink:href="cmpo-20231231.xsd#cmpo_TopTwoCustomersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_ea5e626e-b945-441b-b464-7fdd07d80f84" xlink:to="loc_cmpo_TopTwoCustomersMember_dcb3153c-0aa6-4d95-99f1-c8ac9dd03881" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_add57f3a-6347-4b12-b441-53b2cbc8bb8c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_1b46a670-4e18-4904-93de-6ce4b14cdb20" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_add57f3a-6347-4b12-b441-53b2cbc8bb8c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/PROPERTYANDEQUIPMENTSummaryofpropertyandequipmentDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#PROPERTYANDEQUIPMENTSummaryofpropertyandequipmentDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/PROPERTYANDEQUIPMENTSummaryofpropertyandequipmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_85ec5f42-729f-4b09-9eea-d47446ea5345" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ab949bce-abbb-4d83-a3f8-d20634fbf407" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_85ec5f42-729f-4b09-9eea-d47446ea5345" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ab949bce-abbb-4d83-a3f8-d20634fbf407" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_a806dca8-8e01-4c62-ae5a-eb1816c30a04" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ab949bce-abbb-4d83-a3f8-d20634fbf407" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_a806dca8-8e01-4c62-ae5a-eb1816c30a04" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_a806dca8-8e01-4c62-ae5a-eb1816c30a04_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_a806dca8-8e01-4c62-ae5a-eb1816c30a04" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_a806dca8-8e01-4c62-ae5a-eb1816c30a04_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_14878811-6a86-403d-9c2f-1acd8070b8ad" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_a806dca8-8e01-4c62-ae5a-eb1816c30a04" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_14878811-6a86-403d-9c2f-1acd8070b8ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_6b13deb2-53df-4aa9-8ee6-084bf14fc825" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_14878811-6a86-403d-9c2f-1acd8070b8ad" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_6b13deb2-53df-4aa9-8ee6-084bf14fc825" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_ae6e13fb-cbd4-4d44-b5f0-792e66fd36b3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_14878811-6a86-403d-9c2f-1acd8070b8ad" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_ae6e13fb-cbd4-4d44-b5f0-792e66fd36b3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComputerEquipmentMember_8d64753b-3efd-4b6b-89c1-2f56d93f0293" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ComputerEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_14878811-6a86-403d-9c2f-1acd8070b8ad" xlink:to="loc_us-gaap_ComputerEquipmentMember_8d64753b-3efd-4b6b-89c1-2f56d93f0293" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_79a8f474-64e6-42e1-88a2-e8b7348ea6d8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_14878811-6a86-403d-9c2f-1acd8070b8ad" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_79a8f474-64e6-42e1-88a2-e8b7348ea6d8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VehiclesMember_7a856ba4-2dd2-4f59-bcb9-af6f086c6fd6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VehiclesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_14878811-6a86-403d-9c2f-1acd8070b8ad" xlink:to="loc_us-gaap_VehiclesMember_7a856ba4-2dd2-4f59-bcb9-af6f086c6fd6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_8c5d192d-d35c-4568-b354-c899c4849983" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SoftwareAndSoftwareDevelopmentCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_14878811-6a86-403d-9c2f-1acd8070b8ad" xlink:to="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_8c5d192d-d35c-4568-b354-c899c4849983" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressMember_20434ea3-7b74-4f9a-8aa5-04c9a47180fd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConstructionInProgressMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_14878811-6a86-403d-9c2f-1acd8070b8ad" xlink:to="loc_us-gaap_ConstructionInProgressMember_20434ea3-7b74-4f9a-8aa5-04c9a47180fd" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_9ebd2b36-f15c-489a-b0cb-fcacfb6bc6e5" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ab949bce-abbb-4d83-a3f8-d20634fbf407" xlink:to="loc_srt_RangeAxis_9ebd2b36-f15c-489a-b0cb-fcacfb6bc6e5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_9ebd2b36-f15c-489a-b0cb-fcacfb6bc6e5_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_9ebd2b36-f15c-489a-b0cb-fcacfb6bc6e5" xlink:to="loc_srt_RangeMember_9ebd2b36-f15c-489a-b0cb-fcacfb6bc6e5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_ce472f6e-bf12-4c7d-8a41-d20135ffbb9b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_9ebd2b36-f15c-489a-b0cb-fcacfb6bc6e5" xlink:to="loc_srt_RangeMember_ce472f6e-bf12-4c7d-8a41-d20135ffbb9b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_5aa589b3-34f2-4502-b66d-a3577b1d5251" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_ce472f6e-bf12-4c7d-8a41-d20135ffbb9b" xlink:to="loc_srt_MinimumMember_5aa589b3-34f2-4502-b66d-a3577b1d5251" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_7448e896-eb1f-4462-8f13-41a32c392c66" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_ce472f6e-bf12-4c7d-8a41-d20135ffbb9b" xlink:to="loc_srt_MaximumMember_7448e896-eb1f-4462-8f13-41a32c392c66" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_4842f03b-7bce-43c1-8225-1487693cbfe7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_85ec5f42-729f-4b09-9eea-d47446ea5345" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_4842f03b-7bce-43c1-8225-1487693cbfe7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_8c6b9cae-84a0-4261-a687-1de7194c3eb7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_85ec5f42-729f-4b09-9eea-d47446ea5345" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_8c6b9cae-84a0-4261-a687-1de7194c3eb7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_4ef58ac1-ce15-4f7f-80eb-3d24dea0f8fc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_85ec5f42-729f-4b09-9eea-d47446ea5345" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_4ef58ac1-ce15-4f7f-80eb-3d24dea0f8fc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_a50f622e-c3e9-4d3a-90ea-1a8d635ba4b5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_85ec5f42-729f-4b09-9eea-d47446ea5345" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_a50f622e-c3e9-4d3a-90ea-1a8d635ba4b5" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/DEBTNarrativeDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#DEBTNarrativeDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/DEBTNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_295ed5e7-fa8f-4798-a254-bf3c6055edcb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_DebtInstrumentTable_295ed5e7-fa8f-4798-a254-bf3c6055edcb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_6dde3f87-b89e-4e49-a579-43b8902ed428" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_295ed5e7-fa8f-4798-a254-bf3c6055edcb" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_6dde3f87-b89e-4e49-a579-43b8902ed428" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_6dde3f87-b89e-4e49-a579-43b8902ed428_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_6dde3f87-b89e-4e49-a579-43b8902ed428" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_6dde3f87-b89e-4e49-a579-43b8902ed428_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_542af2f3-287f-470b-bbd3-ba18f968827d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_6dde3f87-b89e-4e49-a579-43b8902ed428" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_542af2f3-287f-470b-bbd3-ba18f968827d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtMember_18739ae5-737d-48cd-a1c5-9f2d29a5d4c1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConvertibleDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_542af2f3-287f-470b-bbd3-ba18f968827d" xlink:to="loc_us-gaap_ConvertibleDebtMember_18739ae5-737d-48cd-a1c5-9f2d29a5d4c1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_LineOfCreditAndTermLoanMember_44efd1f8-67e5-4913-b330-56c88e83a6f2" xlink:href="cmpo-20231231.xsd#cmpo_LineOfCreditAndTermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_542af2f3-287f-470b-bbd3-ba18f968827d" xlink:to="loc_cmpo_LineOfCreditAndTermLoanMember_44efd1f8-67e5-4913-b330-56c88e83a6f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_4dc67ef0-086a-4d57-95b6-2da31ee7e676" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_LineOfCreditAndTermLoanMember_44efd1f8-67e5-4913-b330-56c88e83a6f2" xlink:to="loc_us-gaap_LineOfCreditMember_4dc67ef0-086a-4d57-95b6-2da31ee7e676" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_f26d8e31-7701-4332-b93b-5094842b0c9d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_LineOfCreditAndTermLoanMember_44efd1f8-67e5-4913-b330-56c88e83a6f2" xlink:to="loc_us-gaap_SecuredDebtMember_f26d8e31-7701-4332-b93b-5094842b0c9d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_c5e3ff25-7760-4112-90a4-59f67936c508" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_295ed5e7-fa8f-4798-a254-bf3c6055edcb" xlink:to="loc_us-gaap_StatementClassOfStockAxis_c5e3ff25-7760-4112-90a4-59f67936c508" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_c5e3ff25-7760-4112-90a4-59f67936c508_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_c5e3ff25-7760-4112-90a4-59f67936c508" xlink:to="loc_us-gaap_ClassOfStockDomain_c5e3ff25-7760-4112-90a4-59f67936c508_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_f6ff9d90-26ff-4a22-9090-59d74448d283" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_c5e3ff25-7760-4112-90a4-59f67936c508" xlink:to="loc_us-gaap_ClassOfStockDomain_f6ff9d90-26ff-4a22-9090-59d74448d283" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_51cf312f-9185-414e-ae54-9dc5fab2d14a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_f6ff9d90-26ff-4a22-9090-59d74448d283" xlink:to="loc_us-gaap_CommonClassAMember_51cf312f-9185-414e-ae54-9dc5fab2d14a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_65bde182-abf6-4aff-94cc-a28cd52adb7d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_295ed5e7-fa8f-4798-a254-bf3c6055edcb" xlink:to="loc_us-gaap_DebtInstrumentAxis_65bde182-abf6-4aff-94cc-a28cd52adb7d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_65bde182-abf6-4aff-94cc-a28cd52adb7d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_65bde182-abf6-4aff-94cc-a28cd52adb7d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_65bde182-abf6-4aff-94cc-a28cd52adb7d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_c2bb36a2-a9a9-45b3-8cc5-574d0a2bb66c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_65bde182-abf6-4aff-94cc-a28cd52adb7d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_c2bb36a2-a9a9-45b3-8cc5-574d0a2bb66c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_CreditFacility2016Member_021b0af4-1dd3-4e65-8b25-a5fde0770936" xlink:href="cmpo-20231231.xsd#cmpo_CreditFacility2016Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c2bb36a2-a9a9-45b3-8cc5-574d0a2bb66c" xlink:to="loc_cmpo_CreditFacility2016Member_021b0af4-1dd3-4e65-8b25-a5fde0770936" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_A2021CreditFacilityMember_88097630-7a90-49d4-9aca-74259d949ced" xlink:href="cmpo-20231231.xsd#cmpo_A2021CreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c2bb36a2-a9a9-45b3-8cc5-574d0a2bb66c" xlink:to="loc_cmpo_A2021CreditFacilityMember_88097630-7a90-49d4-9aca-74259d949ced" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_39902188-2ff8-4bd7-9e47-574f9da36aa7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_295ed5e7-fa8f-4798-a254-bf3c6055edcb" xlink:to="loc_us-gaap_CreditFacilityAxis_39902188-2ff8-4bd7-9e47-574f9da36aa7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_39902188-2ff8-4bd7-9e47-574f9da36aa7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_39902188-2ff8-4bd7-9e47-574f9da36aa7" xlink:to="loc_us-gaap_CreditFacilityDomain_39902188-2ff8-4bd7-9e47-574f9da36aa7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_98517d30-6e66-431b-ab6f-79a07a21f446" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_39902188-2ff8-4bd7-9e47-574f9da36aa7" xlink:to="loc_us-gaap_CreditFacilityDomain_98517d30-6e66-431b-ab6f-79a07a21f446" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_55ebd78e-2363-4d77-9f95-e32e5d360ef6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_98517d30-6e66-431b-ab6f-79a07a21f446" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_55ebd78e-2363-4d77-9f95-e32e5d360ef6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_8dbbe9d9-1bac-4993-ba49-7a15e7f19a01" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_295ed5e7-fa8f-4798-a254-bf3c6055edcb" xlink:to="loc_us-gaap_VariableRateAxis_8dbbe9d9-1bac-4993-ba49-7a15e7f19a01" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_8dbbe9d9-1bac-4993-ba49-7a15e7f19a01_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_8dbbe9d9-1bac-4993-ba49-7a15e7f19a01" xlink:to="loc_us-gaap_VariableRateDomain_8dbbe9d9-1bac-4993-ba49-7a15e7f19a01_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_153478e4-c1d5-4a43-839c-ac6a563bd004" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_8dbbe9d9-1bac-4993-ba49-7a15e7f19a01" xlink:to="loc_us-gaap_VariableRateDomain_153478e4-c1d5-4a43-839c-ac6a563bd004" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_SecuredOvernightFinancingRateSOFRMember_eaca18ac-487a-4257-8efb-ba5bc7f7318b" xlink:href="cmpo-20231231.xsd#cmpo_SecuredOvernightFinancingRateSOFRMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_153478e4-c1d5-4a43-839c-ac6a563bd004" xlink:to="loc_cmpo_SecuredOvernightFinancingRateSOFRMember_eaca18ac-487a-4257-8efb-ba5bc7f7318b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrimeRateMember_99b72907-494f-4d95-97e6-7bf5b875baf5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PrimeRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_153478e4-c1d5-4a43-839c-ac6a563bd004" xlink:to="loc_us-gaap_PrimeRateMember_99b72907-494f-4d95-97e6-7bf5b875baf5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_3a085075-e119-40bf-953d-c9e50aca0a23" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_295ed5e7-fa8f-4798-a254-bf3c6055edcb" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_3a085075-e119-40bf-953d-c9e50aca0a23" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_3a085075-e119-40bf-953d-c9e50aca0a23_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_3a085075-e119-40bf-953d-c9e50aca0a23" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_3a085075-e119-40bf-953d-c9e50aca0a23_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_eb332c34-266b-4eb5-9c0e-a0c5dd524564" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_3a085075-e119-40bf-953d-c9e50aca0a23" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_eb332c34-266b-4eb5-9c0e-a0c5dd524564" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_951511de-1e92-40da-a4dd-a73b16520f2e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_eb332c34-266b-4eb5-9c0e-a0c5dd524564" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_951511de-1e92-40da-a4dd-a73b16520f2e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_84fd4db3-ae1a-4969-8df7-9b77ac74a416" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_eb332c34-266b-4eb5-9c0e-a0c5dd524564" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_84fd4db3-ae1a-4969-8df7-9b77ac74a416" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_16005674-d9df-403c-bc09-be4d92a2fe31" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_295ed5e7-fa8f-4798-a254-bf3c6055edcb" xlink:to="loc_srt_RangeAxis_16005674-d9df-403c-bc09-be4d92a2fe31" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_16005674-d9df-403c-bc09-be4d92a2fe31_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_16005674-d9df-403c-bc09-be4d92a2fe31" xlink:to="loc_srt_RangeMember_16005674-d9df-403c-bc09-be4d92a2fe31_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_e9ab8c5a-e077-4efe-bfa9-370bb5c0797f" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_16005674-d9df-403c-bc09-be4d92a2fe31" xlink:to="loc_srt_RangeMember_e9ab8c5a-e077-4efe-bfa9-370bb5c0797f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_47106ac9-f8ff-4a08-abd2-5269c00054fe" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e9ab8c5a-e077-4efe-bfa9-370bb5c0797f" xlink:to="loc_srt_MinimumMember_47106ac9-f8ff-4a08-abd2-5269c00054fe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_80ad1979-6816-4d3f-97b2-7fad6687b3a6" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e9ab8c5a-e077-4efe-bfa9-370bb5c0797f" xlink:to="loc_srt_MaximumMember_80ad1979-6816-4d3f-97b2-7fad6687b3a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_63261c07-4411-4a59-93bc-d4a886bde918" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_63261c07-4411-4a59-93bc-d4a886bde918" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_f19faaca-4d43-4468-93cd-5f9c9095a153" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentConvertibleConversionPrice1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_f19faaca-4d43-4468-93cd-5f9c9095a153" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_fe5fd67f-0ec2-4cb0-8ecb-5592b363a043" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_fe5fd67f-0ec2-4cb0-8ecb-5592b363a043" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTerm_51fd5e1c-ad74-45b9-8008-36dc31885007" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_DebtInstrumentTerm_51fd5e1c-ad74-45b9-8008-36dc31885007" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DebtInstrumentRedemptionPeriodFromClosingDate_2df49815-d3c8-4bc6-a025-b062705ed0e5" xlink:href="cmpo-20231231.xsd#cmpo_DebtInstrumentRedemptionPeriodFromClosingDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_cmpo_DebtInstrumentRedemptionPeriodFromClosingDate_2df49815-d3c8-4bc6-a025-b062705ed0e5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DebtInstrumentRedemptionSharePricePercentageThreshold_ea8a7eaf-335e-442d-9afc-0f55f8b1fd72" xlink:href="cmpo-20231231.xsd#cmpo_DebtInstrumentRedemptionSharePricePercentageThreshold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_cmpo_DebtInstrumentRedemptionSharePricePercentageThreshold_ea8a7eaf-335e-442d-9afc-0f55f8b1fd72" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DebtInstrumentRedemptionThresholdTradingDays_7fede35c-b876-400b-9d2b-ce59798fc524" xlink:href="cmpo-20231231.xsd#cmpo_DebtInstrumentRedemptionThresholdTradingDays"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_cmpo_DebtInstrumentRedemptionThresholdTradingDays_7fede35c-b876-400b-9d2b-ce59798fc524" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DebtInstrumentRedemptionThresholdConsecutiveTradingDays_61933cb4-8728-4bbb-aca0-8b2d47efe865" xlink:href="cmpo-20231231.xsd#cmpo_DebtInstrumentRedemptionThresholdConsecutiveTradingDays"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_cmpo_DebtInstrumentRedemptionThresholdConsecutiveTradingDays_61933cb4-8728-4bbb-aca0-8b2d47efe865" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DebtInstrumentRedemptionRedemptionNoticePeriod_52e4b62d-d44e-431e-a52d-0b7c9839a660" xlink:href="cmpo-20231231.xsd#cmpo_DebtInstrumentRedemptionRedemptionNoticePeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_cmpo_DebtInstrumentRedemptionRedemptionNoticePeriod_52e4b62d-d44e-431e-a52d-0b7c9839a660" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_4bcd5d1f-44a7-40d1-8889-80f2a1a119a0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentRedemptionPricePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_4bcd5d1f-44a7-40d1-8889-80f2a1a119a0" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ConvertibleDebtRedemptionVolumeWeightedAveragePriceThresholdTradingDays_67968eaa-8c79-41b4-8285-0755c0b682f3" xlink:href="cmpo-20231231.xsd#cmpo_ConvertibleDebtRedemptionVolumeWeightedAveragePriceThresholdTradingDays"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_cmpo_ConvertibleDebtRedemptionVolumeWeightedAveragePriceThresholdTradingDays_67968eaa-8c79-41b4-8285-0755c0b682f3" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_05d94095-d811-4c51-8b79-95e69a2b2d61" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_05d94095-d811-4c51-8b79-95e69a2b2d61" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleConversionRatio1_4e2d629b-074c-4e8a-9569-92c1cab8f9b9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentConvertibleConversionRatio1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_DebtInstrumentConvertibleConversionRatio1_4e2d629b-074c-4e8a-9569-92c1cab8f9b9" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DebtInstrumentConvertibleAntiDilutionPeriodAfterCommonStockIssuance_7b08cb3e-b05a-4f33-b994-98e97c956609" xlink:href="cmpo-20231231.xsd#cmpo_DebtInstrumentConvertibleAntiDilutionPeriodAfterCommonStockIssuance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_cmpo_DebtInstrumentConvertibleAntiDilutionPeriodAfterCommonStockIssuance_7b08cb3e-b05a-4f33-b994-98e97c956609" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DebtInstrumentConvertibleAntiDilutionThresholdConsecutiveTradingDays_157bb30b-261d-4cda-8934-4e8137755cc8" xlink:href="cmpo-20231231.xsd#cmpo_DebtInstrumentConvertibleAntiDilutionThresholdConsecutiveTradingDays"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_cmpo_DebtInstrumentConvertibleAntiDilutionThresholdConsecutiveTradingDays_157bb30b-261d-4cda-8934-4e8137755cc8" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DebtInstrumentConvertibleFundamentalChangeRepurchasePricePercentage_e050cce9-9f7d-467f-84aa-5988e3ef9e9b" xlink:href="cmpo-20231231.xsd#cmpo_DebtInstrumentConvertibleFundamentalChangeRepurchasePricePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_cmpo_DebtInstrumentConvertibleFundamentalChangeRepurchasePricePercentage_e050cce9-9f7d-467f-84aa-5988e3ef9e9b" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DebtInstrumentConvertibleRegistrationDefaultInterestRateForFirst90Days_cfee2e5a-e591-49f1-99d2-564b2733a0bc" xlink:href="cmpo-20231231.xsd#cmpo_DebtInstrumentConvertibleRegistrationDefaultInterestRateForFirst90Days"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_cmpo_DebtInstrumentConvertibleRegistrationDefaultInterestRateForFirst90Days_cfee2e5a-e591-49f1-99d2-564b2733a0bc" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DebtInstrumentConvertibleRegistrationDefaultInterestRateAfterFirst90Days_551cc8cc-d1ea-4bd9-9587-972eb374cb01" xlink:href="cmpo-20231231.xsd#cmpo_DebtInstrumentConvertibleRegistrationDefaultInterestRateAfterFirst90Days"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_cmpo_DebtInstrumentConvertibleRegistrationDefaultInterestRateAfterFirst90Days_551cc8cc-d1ea-4bd9-9587-972eb374cb01" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DebtInstrumentConvertibleEventOfDefaultThresholdPercentageOfNoteHoldersMayDeclareNotesPayableImmediately_fe1af535-389e-46ff-bdf8-b6b848f16e84" xlink:href="cmpo-20231231.xsd#cmpo_DebtInstrumentConvertibleEventOfDefaultThresholdPercentageOfNoteHoldersMayDeclareNotesPayableImmediately"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_cmpo_DebtInstrumentConvertibleEventOfDefaultThresholdPercentageOfNoteHoldersMayDeclareNotesPayableImmediately_fe1af535-389e-46ff-bdf8-b6b848f16e84" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DebtInstrumentConvertibleEventOfDefaultPercentageOfNotesPayableImmediately_d9cd3278-45d2-41f2-a0c0-ac4c03faacc9" xlink:href="cmpo-20231231.xsd#cmpo_DebtInstrumentConvertibleEventOfDefaultPercentageOfNotesPayableImmediately"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_cmpo_DebtInstrumentConvertibleEventOfDefaultPercentageOfNotesPayableImmediately_d9cd3278-45d2-41f2-a0c0-ac4c03faacc9" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DebtInstrumentConvertibleEventOfDefaultInterestRateForFirst90Days_92978fbe-7020-4969-b809-6dd165861e64" xlink:href="cmpo-20231231.xsd#cmpo_DebtInstrumentConvertibleEventOfDefaultInterestRateForFirst90Days"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_cmpo_DebtInstrumentConvertibleEventOfDefaultInterestRateForFirst90Days_92978fbe-7020-4969-b809-6dd165861e64" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DebtInstrumentConvertibleEventOfDefaultInterestRateForDays91To180_ef9411ea-9fd7-43d7-8792-c39634b44ce6" xlink:href="cmpo-20231231.xsd#cmpo_DebtInstrumentConvertibleEventOfDefaultInterestRateForDays91To180"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_cmpo_DebtInstrumentConvertibleEventOfDefaultInterestRateForDays91To180_ef9411ea-9fd7-43d7-8792-c39634b44ce6" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability_8840342e-abf9-4418-b409-b6a350903a19" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability_8840342e-abf9-4418-b409-b6a350903a19" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmbeddedDerivativeGainLossOnEmbeddedDerivativeNet_8ffbfd80-ee95-47ca-a0c1-6940dc8ba2a5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmbeddedDerivativeGainLossOnEmbeddedDerivativeNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_EmbeddedDerivativeGainLossOnEmbeddedDerivativeNet_8ffbfd80-ee95-47ca-a0c1-6940dc8ba2a5" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebt_80b1987e-07ff-4219-a440-def6f0e2ee87" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestExpenseDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_InterestExpenseDebt_80b1987e-07ff-4219-a440-def6f0e2ee87" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_c23564d4-00a5-4264-926d-391619c2b42e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_c23564d4-00a5-4264-926d-391619c2b42e" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsGross_0451ae67-684f-416f-9b41-610b1c137ad8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredFinanceCostsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_DeferredFinanceCostsGross_0451ae67-684f-416f-9b41-610b1c137ad8" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_0afab6ea-03e8-4c14-810b-c1587ab80d2b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_0afab6ea-03e8-4c14-810b-c1587ab80d2b" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_ee6127e3-7808-416b-a2df-c06bac10d58f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_ee6127e3-7808-416b-a2df-c06bac10d58f" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_795d4d22-1b9c-4211-b349-6419ea69be20" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WriteOffOfDeferredDebtIssuanceCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_795d4d22-1b9c-4211-b349-6419ea69be20" xlink:type="arc" order="29"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_249711f2-c510-416d-aa6c-5c983984b914" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_249711f2-c510-416d-aa6c-5c983984b914" xlink:type="arc" order="30"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfSecuredDebt_02728980-174b-48ad-9aa9-f18fb6356630" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RepaymentsOfSecuredDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_RepaymentsOfSecuredDebt_02728980-174b-48ad-9aa9-f18fb6356630" xlink:type="arc" order="31"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_0f928ea4-5238-4323-86fd-56436f4a0742" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_LineOfCredit_0f928ea4-5238-4323-86fd-56436f4a0742" xlink:type="arc" order="32"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_8e9f45bc-1b27-4b00-854c-05b22025cdec" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_8e9f45bc-1b27-4b00-854c-05b22025cdec" xlink:type="arc" order="33"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeGainLossOnDerivativeNet_d15ff42e-fcec-45f5-addb-79fd15e3d209" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeGainLossOnDerivativeNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_DerivativeGainLossOnDerivativeNet_d15ff42e-fcec-45f5-addb-79fd15e3d209" xlink:type="arc" order="34"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeGainLossStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_1a0aecbb-80e0-43e3-a810-094f1c500942" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeGainLossStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeGainLossOnDerivativeNet_d15ff42e-fcec-45f5-addb-79fd15e3d209" xlink:to="loc_us-gaap_DerivativeGainLossStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_1a0aecbb-80e0-43e3-a810-094f1c500942" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_c778c311-a13b-43db-95ff-c1624ad182a9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_DerivativeNotionalAmount_c778c311-a13b-43db-95ff-c1624ad182a9" xlink:type="arc" order="35"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_eed24686-e21a-4be0-95e0-e6f554c4b10e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_aa35d8b3-4a34-4771-82e4-a74721026c50" xlink:to="loc_us-gaap_DerivativeAssets_eed24686-e21a-4be0-95e0-e6f554c4b10e" xlink:type="arc" order="36"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/DEBTBalancesPayablebyDebtInstrumentDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#DEBTBalancesPayablebyDebtInstrumentDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/DEBTBalancesPayablebyDebtInstrumentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_a6702576-3771-4684-b89c-a548113b1738" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_48b88e6b-166e-4aee-b376-f0483cea9d9b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_a6702576-3771-4684-b89c-a548113b1738" xlink:to="loc_us-gaap_DebtInstrumentTable_48b88e6b-166e-4aee-b376-f0483cea9d9b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_00a7dd98-776d-44f6-a5a5-9c053c37fc82" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_48b88e6b-166e-4aee-b376-f0483cea9d9b" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_00a7dd98-776d-44f6-a5a5-9c053c37fc82" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_00a7dd98-776d-44f6-a5a5-9c053c37fc82_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_00a7dd98-776d-44f6-a5a5-9c053c37fc82" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_00a7dd98-776d-44f6-a5a5-9c053c37fc82_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_6662d8c4-fdb4-40ce-8fbf-6502edce7421" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_00a7dd98-776d-44f6-a5a5-9c053c37fc82" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_6662d8c4-fdb4-40ce-8fbf-6502edce7421" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_c4f7ac4e-0a1b-4df8-a131-b38a3fe00280" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_6662d8c4-fdb4-40ce-8fbf-6502edce7421" xlink:to="loc_us-gaap_SecuredDebtMember_c4f7ac4e-0a1b-4df8-a131-b38a3fe00280" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtMember_a85b1097-fc45-4bd8-8b15-8a431444b30e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConvertibleDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_6662d8c4-fdb4-40ce-8fbf-6502edce7421" xlink:to="loc_us-gaap_ConvertibleDebtMember_a85b1097-fc45-4bd8-8b15-8a431444b30e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_2dcefeee-ce63-4860-bec5-9a58e14a64e0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_a6702576-3771-4684-b89c-a548113b1738" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_2dcefeee-ce63-4860-bec5-9a58e14a64e0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_14d4ae56-eac4-4434-88f6-5fe2464109d3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_a6702576-3771-4684-b89c-a548113b1738" xlink:to="loc_us-gaap_LongTermDebtCurrent_14d4ae56-eac4-4434-88f6-5fe2464109d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_121c62ce-0662-4445-9c1b-90d8537faac3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_a6702576-3771-4684-b89c-a548113b1738" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_121c62ce-0662-4445-9c1b-90d8537faac3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_f8555a6e-f0e3-4f89-ba1b-9b563000dd31" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_a6702576-3771-4684-b89c-a548113b1738" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_f8555a6e-f0e3-4f89-ba1b-9b563000dd31" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability_161b7496-d675-4862-a07d-9c7c4b6fd277" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_a6702576-3771-4684-b89c-a548113b1738" xlink:to="loc_us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability_161b7496-d675-4862-a07d-9c7c4b6fd277" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/LEASESNarrativeDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#LEASESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/LEASESNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_669f811c-252d-4a5b-92e4-619e711341c1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_ecb3ebcd-2604-412b-a213-c5356bc9ce7b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_669f811c-252d-4a5b-92e4-619e711341c1" xlink:to="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_ecb3ebcd-2604-412b-a213-c5356bc9ce7b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_b338c85f-e84b-48f7-9687-0b0a57a1fe2e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_ecb3ebcd-2604-412b-a213-c5356bc9ce7b" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_b338c85f-e84b-48f7-9687-0b0a57a1fe2e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfAdoptionMember_b338c85f-e84b-48f7-9687-0b0a57a1fe2e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TypeOfAdoptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_b338c85f-e84b-48f7-9687-0b0a57a1fe2e" xlink:to="loc_us-gaap_TypeOfAdoptionMember_b338c85f-e84b-48f7-9687-0b0a57a1fe2e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfAdoptionMember_5fdfd3b3-d4ff-4f05-bdaa-a21db540357e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TypeOfAdoptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_b338c85f-e84b-48f7-9687-0b0a57a1fe2e" xlink:to="loc_us-gaap_TypeOfAdoptionMember_5fdfd3b3-d4ff-4f05-bdaa-a21db540357e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountingStandardsUpdate201602Member_461aa88a-c5e5-4200-9964-1c1a29f5698b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountingStandardsUpdate201602Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_5fdfd3b3-d4ff-4f05-bdaa-a21db540357e" xlink:to="loc_us-gaap_AccountingStandardsUpdate201602Member_461aa88a-c5e5-4200-9964-1c1a29f5698b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_f507486c-9c2c-459b-a517-5dd7b93d9c93" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_ecb3ebcd-2604-412b-a213-c5356bc9ce7b" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_f507486c-9c2c-459b-a517-5dd7b93d9c93" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_f507486c-9c2c-459b-a517-5dd7b93d9c93_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_f507486c-9c2c-459b-a517-5dd7b93d9c93" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_f507486c-9c2c-459b-a517-5dd7b93d9c93_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_6e6327d4-4432-4cb7-9d66-fcf4ce7381db" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_f507486c-9c2c-459b-a517-5dd7b93d9c93" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_6e6327d4-4432-4cb7-9d66-fcf4ce7381db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_e16aeac1-0a42-4000-96f0-d4a0d24f0e63" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_6e6327d4-4432-4cb7-9d66-fcf4ce7381db" xlink:to="loc_us-gaap_LineOfCreditMember_e16aeac1-0a42-4000-96f0-d4a0d24f0e63" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_d534a60c-db89-4403-ab86-5a01a5d15d1f" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_ecb3ebcd-2604-412b-a213-c5356bc9ce7b" xlink:to="loc_srt_RangeAxis_d534a60c-db89-4403-ab86-5a01a5d15d1f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_d534a60c-db89-4403-ab86-5a01a5d15d1f_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_d534a60c-db89-4403-ab86-5a01a5d15d1f" xlink:to="loc_srt_RangeMember_d534a60c-db89-4403-ab86-5a01a5d15d1f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_e5db1fdc-4c96-44ca-9fa2-097a03a1909a" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_d534a60c-db89-4403-ab86-5a01a5d15d1f" xlink:to="loc_srt_RangeMember_e5db1fdc-4c96-44ca-9fa2-097a03a1909a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_083a8be1-80f1-4c76-a2dc-5d662ed6a20a" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e5db1fdc-4c96-44ca-9fa2-097a03a1909a" xlink:to="loc_srt_MinimumMember_083a8be1-80f1-4c76-a2dc-5d662ed6a20a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_e448ef3a-0aa5-4794-b5ec-9d379099bc5f" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e5db1fdc-4c96-44ca-9fa2-097a03a1909a" xlink:to="loc_srt_MaximumMember_e448ef3a-0aa5-4794-b5ec-9d379099bc5f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_7dfbb74f-1280-42ec-baa9-e303688abe92" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_ecb3ebcd-2604-412b-a213-c5356bc9ce7b" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_7dfbb74f-1280-42ec-baa9-e303688abe92" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_7dfbb74f-1280-42ec-baa9-e303688abe92_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_7dfbb74f-1280-42ec-baa9-e303688abe92" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_7dfbb74f-1280-42ec-baa9-e303688abe92_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e5ab6ae7-30e9-447d-bebf-ebf36f8db792" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_7dfbb74f-1280-42ec-baa9-e303688abe92" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e5ab6ae7-30e9-447d-bebf-ebf36f8db792" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_OfficeBuildingAndManufacturingFacilityLocation1Member_00b50192-f283-4cce-b05a-acee7dd25926" xlink:href="cmpo-20231231.xsd#cmpo_OfficeBuildingAndManufacturingFacilityLocation1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e5ab6ae7-30e9-447d-bebf-ebf36f8db792" xlink:to="loc_cmpo_OfficeBuildingAndManufacturingFacilityLocation1Member_00b50192-f283-4cce-b05a-acee7dd25926" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_OfficeBuildingAndManufacturingFacilityLocation2Member_0bede4ed-c202-424d-b8d3-3dc1fb295103" xlink:href="cmpo-20231231.xsd#cmpo_OfficeBuildingAndManufacturingFacilityLocation2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e5ab6ae7-30e9-447d-bebf-ebf36f8db792" xlink:to="loc_cmpo_OfficeBuildingAndManufacturingFacilityLocation2Member_0bede4ed-c202-424d-b8d3-3dc1fb295103" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_OfficeBuildingAndManufacturingFacilityLocation3Member_8bbf2f6b-dc2f-4ec0-a1af-5e4803c0a5e8" xlink:href="cmpo-20231231.xsd#cmpo_OfficeBuildingAndManufacturingFacilityLocation3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e5ab6ae7-30e9-447d-bebf-ebf36f8db792" xlink:to="loc_cmpo_OfficeBuildingAndManufacturingFacilityLocation3Member_8bbf2f6b-dc2f-4ec0-a1af-5e4803c0a5e8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_SomersetNewJerseyWarehouseMember_e3ecdbb3-ac28-4bf7-ac7b-282029b88fe5" xlink:href="cmpo-20231231.xsd#cmpo_SomersetNewJerseyWarehouseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e5ab6ae7-30e9-447d-bebf-ebf36f8db792" xlink:to="loc_cmpo_SomersetNewJerseyWarehouseMember_e3ecdbb3-ac28-4bf7-ac7b-282029b88fe5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_SomersetNewJerseyOfficeMember_e91ec6c6-147a-4e08-914e-30023e59dbad" xlink:href="cmpo-20231231.xsd#cmpo_SomersetNewJerseyOfficeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e5ab6ae7-30e9-447d-bebf-ebf36f8db792" xlink:to="loc_cmpo_SomersetNewJerseyOfficeMember_e91ec6c6-147a-4e08-914e-30023e59dbad" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_77105d6d-803f-479e-9482-32c15b2d9d4f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_669f811c-252d-4a5b-92e4-619e711341c1" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_77105d6d-803f-479e-9482-32c15b2d9d4f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_56cdcb44-5c76-435c-b8e5-b1ddd75f91f3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_669f811c-252d-4a5b-92e4-619e711341c1" xlink:to="loc_us-gaap_OperatingLeaseLiability_56cdcb44-5c76-435c-b8e5-b1ddd75f91f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_08c7f456-8dd2-47ce-a84b-bc83d913534d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_669f811c-252d-4a5b-92e4-619e711341c1" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_08c7f456-8dd2-47ce-a84b-bc83d913534d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_5f19d96f-1d7f-491a-b1a1-dd334c98d671" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityInterestRateDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_669f811c-252d-4a5b-92e4-619e711341c1" xlink:to="loc_us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_5f19d96f-1d7f-491a-b1a1-dd334c98d671" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseRenewalTerm_826f76ab-bed8-4764-8856-849e58e196fd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseRenewalTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_669f811c-252d-4a5b-92e4-619e711341c1" xlink:to="loc_us-gaap_LesseeOperatingLeaseRenewalTerm_826f76ab-bed8-4764-8856-849e58e196fd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseTermOfContract_82b52fe3-8ae7-46e6-b872-d871c6e876ab" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_669f811c-252d-4a5b-92e4-619e711341c1" xlink:to="loc_us-gaap_LesseeOperatingLeaseTermOfContract_82b52fe3-8ae7-46e6-b872-d871c6e876ab" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_LesseeOperatingLeaseBaseRent_1ea3206e-4330-4ea3-a6f1-a26e5132a3f8" xlink:href="cmpo-20231231.xsd#cmpo_LesseeOperatingLeaseBaseRent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_669f811c-252d-4a5b-92e4-619e711341c1" xlink:to="loc_cmpo_LesseeOperatingLeaseBaseRent_1ea3206e-4330-4ea3-a6f1-a26e5132a3f8" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_LesseeOperatingLeaseLeaseEscalationFactor_0fc052f4-3ff9-4e04-a794-79f9afb3f5c5" xlink:href="cmpo-20231231.xsd#cmpo_LesseeOperatingLeaseLeaseEscalationFactor"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_669f811c-252d-4a5b-92e4-619e711341c1" xlink:to="loc_cmpo_LesseeOperatingLeaseLeaseEscalationFactor_0fc052f4-3ff9-4e04-a794-79f9afb3f5c5" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_LesseeOperatingLeaseNumberOfRenewalOptions_705634a7-58c3-4f1f-87b5-e6199631b0da" xlink:href="cmpo-20231231.xsd#cmpo_LesseeOperatingLeaseNumberOfRenewalOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_669f811c-252d-4a5b-92e4-619e711341c1" xlink:to="loc_cmpo_LesseeOperatingLeaseNumberOfRenewalOptions_705634a7-58c3-4f1f-87b5-e6199631b0da" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_a5fdeeb7-39a5-4816-890a-4e58174bc38e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_669f811c-252d-4a5b-92e4-619e711341c1" xlink:to="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_a5fdeeb7-39a5-4816-890a-4e58174bc38e" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_9b4fe41c-7f20-47e9-b3eb-f16d46d68f70" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_669f811c-252d-4a5b-92e4-619e711341c1" xlink:to="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_9b4fe41c-7f20-47e9-b3eb-f16d46d68f70" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseRemainingLeaseTerm_4830ec39-a86f-4b60-9058-3e04fe247b96" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseRemainingLeaseTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_669f811c-252d-4a5b-92e4-619e711341c1" xlink:to="loc_us-gaap_LesseeOperatingLeaseRemainingLeaseTerm_4830ec39-a86f-4b60-9058-3e04fe247b96" xlink:type="arc" order="11"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/EQUITYSTRUCTUREDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#EQUITYSTRUCTUREDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/EQUITYSTRUCTUREDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_69cc0b6b-6fa0-45e6-86c2-f084fbbf2fe6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_dcf26c82-fbc1-4b30-a9a3-08a9138277d5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_69cc0b6b-6fa0-45e6-86c2-f084fbbf2fe6" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_dcf26c82-fbc1-4b30-a9a3-08a9138277d5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_da3fbeb6-9e5a-444c-8262-87950125e7c8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_dcf26c82-fbc1-4b30-a9a3-08a9138277d5" xlink:to="loc_us-gaap_StatementClassOfStockAxis_da3fbeb6-9e5a-444c-8262-87950125e7c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_da3fbeb6-9e5a-444c-8262-87950125e7c8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_da3fbeb6-9e5a-444c-8262-87950125e7c8" xlink:to="loc_us-gaap_ClassOfStockDomain_da3fbeb6-9e5a-444c-8262-87950125e7c8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_e6172baa-34a0-42a3-af63-f7a977f74f72" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_da3fbeb6-9e5a-444c-8262-87950125e7c8" xlink:to="loc_us-gaap_ClassOfStockDomain_e6172baa-34a0-42a3-af63-f7a977f74f72" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_7eb8ac80-2cf2-4e2c-a8b5-a825c93eced6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_e6172baa-34a0-42a3-af63-f7a977f74f72" xlink:to="loc_us-gaap_CommonClassAMember_7eb8ac80-2cf2-4e2c-a8b5-a825c93eced6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_8a7fa5b3-df0e-4041-b910-4b637649b401" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_e6172baa-34a0-42a3-af63-f7a977f74f72" xlink:to="loc_us-gaap_CommonClassBMember_8a7fa5b3-df0e-4041-b910-4b637649b401" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightAxis_e60efe0a-1841-4350-b5dd-d1338fd9e490" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_dcf26c82-fbc1-4b30-a9a3-08a9138277d5" xlink:to="loc_us-gaap_ClassOfWarrantOrRightAxis_e60efe0a-1841-4350-b5dd-d1338fd9e490" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_e60efe0a-1841-4350-b5dd-d1338fd9e490_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_e60efe0a-1841-4350-b5dd-d1338fd9e490" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_e60efe0a-1841-4350-b5dd-d1338fd9e490_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_5445f255-4389-4b96-98fe-2e1944c6c1b0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_e60efe0a-1841-4350-b5dd-d1338fd9e490" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_5445f255-4389-4b96-98fe-2e1944c6c1b0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_PrivateWarrantsMember_a5ade0f4-d38a-4df9-91b1-5b0c876ab95b" xlink:href="cmpo-20231231.xsd#cmpo_PrivateWarrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_5445f255-4389-4b96-98fe-2e1944c6c1b0" xlink:to="loc_cmpo_PrivateWarrantsMember_a5ade0f4-d38a-4df9-91b1-5b0c876ab95b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_PublicWarrantsMember_66a6dd36-430b-44c5-9296-ca9b33e44ec6" xlink:href="cmpo-20231231.xsd#cmpo_PublicWarrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_5445f255-4389-4b96-98fe-2e1944c6c1b0" xlink:to="loc_cmpo_PublicWarrantsMember_66a6dd36-430b-44c5-9296-ca9b33e44ec6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_51b368a3-e6cf-4753-949f-c9b253077f00" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_69cc0b6b-6fa0-45e6-86c2-f084fbbf2fe6" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_51b368a3-e6cf-4753-949f-c9b253077f00" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_72e1a005-d87b-4b79-b54d-8f9c85e38da4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_69cc0b6b-6fa0-45e6-86c2-f084fbbf2fe6" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_72e1a005-d87b-4b79-b54d-8f9c85e38da4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_414b8529-c6c1-477e-af09-e8f42c92157e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_69cc0b6b-6fa0-45e6-86c2-f084fbbf2fe6" xlink:to="loc_us-gaap_CommonStockSharesIssued_414b8529-c6c1-477e-af09-e8f42c92157e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_1037ab72-8402-4fc6-988c-b816437a11b3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_69cc0b6b-6fa0-45e6-86c2-f084fbbf2fe6" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_1037ab72-8402-4fc6-988c-b816437a11b3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_93ab5271-dd7d-42e2-9619-8015c079b20d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_69cc0b6b-6fa0-45e6-86c2-f084fbbf2fe6" xlink:to="loc_us-gaap_PreferredStockSharesIssued_93ab5271-dd7d-42e2-9619-8015c079b20d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_a50dc088-76ad-4fc7-a8db-367f946be2f9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_69cc0b6b-6fa0-45e6-86c2-f084fbbf2fe6" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_a50dc088-76ad-4fc7-a8db-367f946be2f9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightOutstanding_8f8a8a61-c86f-44c8-97ac-9c7ac5d0870a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_69cc0b6b-6fa0-45e6-86c2-f084fbbf2fe6" xlink:to="loc_us-gaap_ClassOfWarrantOrRightOutstanding_8f8a8a61-c86f-44c8-97ac-9c7ac5d0870a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_f12fb48f-1fd7-4d5b-96fc-bf67877f945e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_69cc0b6b-6fa0-45e6-86c2-f084fbbf2fe6" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_f12fb48f-1fd7-4d5b-96fc-bf67877f945e" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ClassOfWarrantOrRightCommencementPeriodFromBusinessCombination_229c42c9-ebb5-476b-97d7-8a9d40d5e5af" xlink:href="cmpo-20231231.xsd#cmpo_ClassOfWarrantOrRightCommencementPeriodFromBusinessCombination"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_69cc0b6b-6fa0-45e6-86c2-f084fbbf2fe6" xlink:to="loc_cmpo_ClassOfWarrantOrRightCommencementPeriodFromBusinessCombination_229c42c9-ebb5-476b-97d7-8a9d40d5e5af" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_c2c15a0d-d739-4c25-9adb-f680d96b834b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_69cc0b6b-6fa0-45e6-86c2-f084fbbf2fe6" xlink:to="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_c2c15a0d-d739-4c25-9adb-f680d96b834b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight_09df82e4-169a-43cc-a64d-98693ed517d6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_69cc0b6b-6fa0-45e6-86c2-f084fbbf2fe6" xlink:to="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight_09df82e4-169a-43cc-a64d-98693ed517d6" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_CommonStockRedemptionValue_114d6c7d-b132-4842-9602-6a39f0395129" xlink:href="cmpo-20231231.xsd#cmpo_CommonStockRedemptionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_69cc0b6b-6fa0-45e6-86c2-f084fbbf2fe6" xlink:to="loc_cmpo_CommonStockRedemptionValue_114d6c7d-b132-4842-9602-6a39f0395129" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharePrice_7027ddb1-2bb7-4b4d-b1fc-48fa0f6e25fe" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_69cc0b6b-6fa0-45e6-86c2-f084fbbf2fe6" xlink:to="loc_us-gaap_SharePrice_7027ddb1-2bb7-4b4d-b1fc-48fa0f6e25fe" xlink:type="arc" order="12"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/EQUITYCOMPENSATIONShareBasedCompensationExpenseDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#EQUITYCOMPENSATIONShareBasedCompensationExpenseDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/EQUITYCOMPENSATIONShareBasedCompensationExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_38d2792a-7b70-48fc-9aea-b21f10739a25" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_446448d9-1da2-46fd-ad21-2f753e808898" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_38d2792a-7b70-48fc-9aea-b21f10739a25" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_446448d9-1da2-46fd-ad21-2f753e808898" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_4aebd998-b96b-4781-a091-30a6b12f7956" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_446448d9-1da2-46fd-ad21-2f753e808898" xlink:to="loc_us-gaap_AwardTypeAxis_4aebd998-b96b-4781-a091-30a6b12f7956" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4aebd998-b96b-4781-a091-30a6b12f7956_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_4aebd998-b96b-4781-a091-30a6b12f7956" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4aebd998-b96b-4781-a091-30a6b12f7956_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_111b59c9-3cc6-465d-b8f3-0730eb5a966b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_4aebd998-b96b-4781-a091-30a6b12f7956" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_111b59c9-3cc6-465d-b8f3-0730eb5a966b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_08d777ea-24d8-4e58-ab4d-119617d75d15" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_111b59c9-3cc6-465d-b8f3-0730eb5a966b" xlink:to="loc_us-gaap_EmployeeStockOptionMember_08d777ea-24d8-4e58-ab4d-119617d75d15" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_EarnoutConsiderationMember_df6c7f2c-5d66-466a-a489-10bbebfa0146" xlink:href="cmpo-20231231.xsd#cmpo_EarnoutConsiderationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_111b59c9-3cc6-465d-b8f3-0730eb5a966b" xlink:to="loc_cmpo_EarnoutConsiderationMember_df6c7f2c-5d66-466a-a489-10bbebfa0146" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_d4f1f4ca-ba81-41b1-a89e-fcfc6d4292ab" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_111b59c9-3cc6-465d-b8f3-0730eb5a966b" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_d4f1f4ca-ba81-41b1-a89e-fcfc6d4292ab" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_85bfc63c-3c1c-4bc6-9018-b63426cea96b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_111b59c9-3cc6-465d-b8f3-0730eb5a966b" xlink:to="loc_us-gaap_PerformanceSharesMember_85bfc63c-3c1c-4bc6-9018-b63426cea96b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockMember_52b88ef3-102b-4c56-9a62-f55ef46855cd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_111b59c9-3cc6-465d-b8f3-0730eb5a966b" xlink:to="loc_us-gaap_EmployeeStockMember_52b88ef3-102b-4c56-9a62-f55ef46855cd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_IncentiveStockUnitsMember_67207f59-f0f4-42f5-9bc3-3808f3250d2d" xlink:href="cmpo-20231231.xsd#cmpo_IncentiveStockUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_111b59c9-3cc6-465d-b8f3-0730eb5a966b" xlink:to="loc_cmpo_IncentiveStockUnitsMember_67207f59-f0f4-42f5-9bc3-3808f3250d2d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_dcc1a3fb-607b-4b3d-830c-1ff5a3c1fa83" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_38d2792a-7b70-48fc-9aea-b21f10739a25" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_dcc1a3fb-607b-4b3d-830c-1ff5a3c1fa83" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/EQUITYCOMPENSATIONNarrativeDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#EQUITYCOMPENSATIONNarrativeDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/EQUITYCOMPENSATIONNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_18d8c7b0-ce3c-4aef-be07-aa383d1442ae" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_18d8c7b0-ce3c-4aef-be07-aa383d1442ae" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_4b4276be-9fb5-49b8-a670-bf4273b04a32" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_18d8c7b0-ce3c-4aef-be07-aa383d1442ae" xlink:to="loc_us-gaap_PlanNameAxis_4b4276be-9fb5-49b8-a670-bf4273b04a32" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_4b4276be-9fb5-49b8-a670-bf4273b04a32_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_4b4276be-9fb5-49b8-a670-bf4273b04a32" xlink:to="loc_us-gaap_PlanNameDomain_4b4276be-9fb5-49b8-a670-bf4273b04a32_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_ebd3ba50-c8ed-4a62-ae4d-94fb34292832" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_4b4276be-9fb5-49b8-a670-bf4273b04a32" xlink:to="loc_us-gaap_PlanNameDomain_ebd3ba50-c8ed-4a62-ae4d-94fb34292832" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_IncentiveEquityPlan2021Member_407f8b6a-1666-489d-9c50-1fcaf38df890" xlink:href="cmpo-20231231.xsd#cmpo_IncentiveEquityPlan2021Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_ebd3ba50-c8ed-4a62-ae4d-94fb34292832" xlink:to="loc_cmpo_IncentiveEquityPlan2021Member_407f8b6a-1666-489d-9c50-1fcaf38df890" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_b8e75a5e-9d2e-4697-b2eb-16f8e1bc7c7e" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_18d8c7b0-ce3c-4aef-be07-aa383d1442ae" xlink:to="loc_srt_RangeAxis_b8e75a5e-9d2e-4697-b2eb-16f8e1bc7c7e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_b8e75a5e-9d2e-4697-b2eb-16f8e1bc7c7e_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_b8e75a5e-9d2e-4697-b2eb-16f8e1bc7c7e" xlink:to="loc_srt_RangeMember_b8e75a5e-9d2e-4697-b2eb-16f8e1bc7c7e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_76ec7405-143c-47f1-80d7-20c65c4cf8a9" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_b8e75a5e-9d2e-4697-b2eb-16f8e1bc7c7e" xlink:to="loc_srt_RangeMember_76ec7405-143c-47f1-80d7-20c65c4cf8a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_233db2f2-298b-4b70-a9cf-47e3d8ac9ce8" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_76ec7405-143c-47f1-80d7-20c65c4cf8a9" xlink:to="loc_srt_MinimumMember_233db2f2-298b-4b70-a9cf-47e3d8ac9ce8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_140ba160-fd9c-4de9-b931-c82d9dc4a49c" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_76ec7405-143c-47f1-80d7-20c65c4cf8a9" xlink:to="loc_srt_MaximumMember_140ba160-fd9c-4de9-b931-c82d9dc4a49c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_10d407cc-2ba8-4a12-bf0f-7a18f6aa963e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_18d8c7b0-ce3c-4aef-be07-aa383d1442ae" xlink:to="loc_us-gaap_AwardTypeAxis_10d407cc-2ba8-4a12-bf0f-7a18f6aa963e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_10d407cc-2ba8-4a12-bf0f-7a18f6aa963e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_10d407cc-2ba8-4a12-bf0f-7a18f6aa963e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_10d407cc-2ba8-4a12-bf0f-7a18f6aa963e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cceb44b5-f173-4b18-845e-f463f1661f7d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_10d407cc-2ba8-4a12-bf0f-7a18f6aa963e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cceb44b5-f173-4b18-845e-f463f1661f7d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_2a92adf3-91b9-44da-a782-a9732b2b4194" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cceb44b5-f173-4b18-845e-f463f1661f7d" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_2a92adf3-91b9-44da-a782-a9732b2b4194" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_82c4a299-2397-4dae-8a23-3b0317ac04a9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cceb44b5-f173-4b18-845e-f463f1661f7d" xlink:to="loc_us-gaap_PerformanceSharesMember_82c4a299-2397-4dae-8a23-3b0317ac04a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockMember_23020fc6-b2ab-4389-995d-fa79f6c9d385" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cceb44b5-f173-4b18-845e-f463f1661f7d" xlink:to="loc_us-gaap_EmployeeStockMember_23020fc6-b2ab-4389-995d-fa79f6c9d385" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_cc3d6281-717f-45ea-b7c5-1edca1d1cde9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cceb44b5-f173-4b18-845e-f463f1661f7d" xlink:to="loc_us-gaap_EmployeeStockOptionMember_cc3d6281-717f-45ea-b7c5-1edca1d1cde9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_EarnoutConsiderationMember_d3145174-c824-4787-99cd-69eb756281ea" xlink:href="cmpo-20231231.xsd#cmpo_EarnoutConsiderationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cceb44b5-f173-4b18-845e-f463f1661f7d" xlink:to="loc_cmpo_EarnoutConsiderationMember_d3145174-c824-4787-99cd-69eb756281ea" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_IncentiveStockUnitsMember_199459b8-24fb-4437-ac06-dd7b815ef86c" xlink:href="cmpo-20231231.xsd#cmpo_IncentiveStockUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cceb44b5-f173-4b18-845e-f463f1661f7d" xlink:to="loc_cmpo_IncentiveStockUnitsMember_199459b8-24fb-4437-ac06-dd7b815ef86c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_08cb13ca-496f-45ec-9bbb-0bd78daa233b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_18d8c7b0-ce3c-4aef-be07-aa383d1442ae" xlink:to="loc_us-gaap_StatementClassOfStockAxis_08cb13ca-496f-45ec-9bbb-0bd78daa233b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_08cb13ca-496f-45ec-9bbb-0bd78daa233b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_08cb13ca-496f-45ec-9bbb-0bd78daa233b" xlink:to="loc_us-gaap_ClassOfStockDomain_08cb13ca-496f-45ec-9bbb-0bd78daa233b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_93592c2b-e7eb-4b15-9b57-2a81c9908758" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_08cb13ca-496f-45ec-9bbb-0bd78daa233b" xlink:to="loc_us-gaap_ClassOfStockDomain_93592c2b-e7eb-4b15-9b57-2a81c9908758" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_5fd58f5e-d147-4c10-bf1c-d0d0e15201d8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_93592c2b-e7eb-4b15-9b57-2a81c9908758" xlink:to="loc_us-gaap_CommonClassBMember_5fd58f5e-d147-4c10-bf1c-d0d0e15201d8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GranteeStatusAxis_3a1867e8-d109-46c8-98d9-973c998e783c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GranteeStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_18d8c7b0-ce3c-4aef-be07-aa383d1442ae" xlink:to="loc_us-gaap_GranteeStatusAxis_3a1867e8-d109-46c8-98d9-973c998e783c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GranteeStatusDomain_3a1867e8-d109-46c8-98d9-973c998e783c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GranteeStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GranteeStatusAxis_3a1867e8-d109-46c8-98d9-973c998e783c" xlink:to="loc_us-gaap_GranteeStatusDomain_3a1867e8-d109-46c8-98d9-973c998e783c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GranteeStatusDomain_e67385fe-511f-4cb7-b5f8-070970a6e4d9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GranteeStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GranteeStatusAxis_3a1867e8-d109-46c8-98d9-973c998e783c" xlink:to="loc_us-gaap_GranteeStatusDomain_e67385fe-511f-4cb7-b5f8-070970a6e4d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedPaymentArrangementEmployeeMember_c67f9041-cf77-482c-a966-d6a3d3fffd8c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedPaymentArrangementEmployeeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GranteeStatusDomain_e67385fe-511f-4cb7-b5f8-070970a6e4d9" xlink:to="loc_us-gaap_ShareBasedPaymentArrangementEmployeeMember_c67f9041-cf77-482c-a966-d6a3d3fffd8c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedPaymentArrangementNonemployeeMember_bd6ddbf5-c766-445d-9dc7-1cfeac557836" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedPaymentArrangementNonemployeeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GranteeStatusDomain_e67385fe-511f-4cb7-b5f8-070970a6e4d9" xlink:to="loc_us-gaap_ShareBasedPaymentArrangementNonemployeeMember_bd6ddbf5-c766-445d-9dc7-1cfeac557836" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_801b691d-7aaf-45a5-9f22-55b065457a29" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_18d8c7b0-ce3c-4aef-be07-aa383d1442ae" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_801b691d-7aaf-45a5-9f22-55b065457a29" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_801b691d-7aaf-45a5-9f22-55b065457a29_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_801b691d-7aaf-45a5-9f22-55b065457a29" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_801b691d-7aaf-45a5-9f22-55b065457a29_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_9de528df-ef25-4b03-9254-51f79074c43c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_801b691d-7aaf-45a5-9f22-55b065457a29" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_9de528df-ef25-4b03-9254-51f79074c43c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_09cf7e7f-8fc5-4744-bcd9-fb85790cb4f0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_9de528df-ef25-4b03-9254-51f79074c43c" xlink:to="loc_us-gaap_SubsequentEventMember_09cf7e7f-8fc5-4744-bcd9-fb85790cb4f0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_99d973d1-d7ed-408e-9992-1e08a3520b9f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_99d973d1-d7ed-408e-9992-1e08a3520b9f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized_cd338419-09bf-4fdc-ae52-528a18f18abe" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized_cd338419-09bf-4fdc-ae52-528a18f18abe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalSharesAuthorizedPercentage_82ae5569-7e2a-47bf-8779-f757c3cfe2d4" xlink:href="cmpo-20231231.xsd#cmpo_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalSharesAuthorizedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_cmpo_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalSharesAuthorizedPercentage_82ae5569-7e2a-47bf-8779-f757c3cfe2d4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_d3fd4f5b-2fbd-4874-aa46-eba689d1f3ee" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_d3fd4f5b-2fbd-4874-aa46-eba689d1f3ee" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_68886191-d238-4c82-b6c5-7719057e581e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_68886191-d238-4c82-b6c5-7719057e581e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_2421ae4c-511c-428d-916e-22409ca9bb2c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_2421ae4c-511c-428d-916e-22409ca9bb2c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate_5f558a23-2f08-4ccd-ae98-e81731e2e3c3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate_5f558a23-2f08-4ccd-ae98-e81731e2e3c3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_ff7261c8-b8b4-42b7-9586-d395783a9c50" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_ff7261c8-b8b4-42b7-9586-d395783a9c50" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_2e76c080-064f-4b6f-8e7c-8ccb7f9b1832" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_2e76c080-064f-4b6f-8e7c-8ccb7f9b1832" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_3384f1be-b7cf-4c52-8b0b-6222452c18fd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_3384f1be-b7cf-4c52-8b0b-6222452c18fd" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_CommonStockVotingRightsNumberOfVotes_be5b0290-6694-4449-9307-bf736327f79e" xlink:href="cmpo-20231231.xsd#cmpo_CommonStockVotingRightsNumberOfVotes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_cmpo_CommonStockVotingRightsNumberOfVotes_be5b0290-6694-4449-9307-bf736327f79e" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_RecapitalizationExchangeRatio_b46b35a4-bdbb-4829-b9e4-037cbfc39627" xlink:href="cmpo-20231231.xsd#cmpo_RecapitalizationExchangeRatio"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_cmpo_RecapitalizationExchangeRatio_b46b35a4-bdbb-4829-b9e4-037cbfc39627" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_c54e47b7-5431-4128-86b4-a5cd1db428fd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_c54e47b7-5431-4128-86b4-a5cd1db428fd" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_298161e4-894d-4700-87c8-0bb37db661fe" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_298161e4-894d-4700-87c8-0bb37db661fe" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ReverseRecapitalizationNumberOfGranteesAffectedByRecapitalization_b594a9b6-c0d8-4de4-8512-216126788e49" xlink:href="cmpo-20231231.xsd#cmpo_ReverseRecapitalizationNumberOfGranteesAffectedByRecapitalization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_cmpo_ReverseRecapitalizationNumberOfGranteesAffectedByRecapitalization_b594a9b6-c0d8-4de4-8512-216126788e49" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DerivativeInstrumentContingentConsiderationLiabilityShares_fded918a-0097-4241-8dc5-23bebff97a51" xlink:href="cmpo-20231231.xsd#cmpo_DerivativeInstrumentContingentConsiderationLiabilityShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_cmpo_DerivativeInstrumentContingentConsiderationLiabilityShares_fded918a-0097-4241-8dc5-23bebff97a51" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ShareBasedCompensationArrangementByShareBasedPaymentAwardsContingentConsiderationShares_78726484-fb5a-4118-8ada-b18cf87bb506" xlink:href="cmpo-20231231.xsd#cmpo_ShareBasedCompensationArrangementByShareBasedPaymentAwardsContingentConsiderationShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_cmpo_ShareBasedCompensationArrangementByShareBasedPaymentAwardsContingentConsiderationShares_78726484-fb5a-4118-8ada-b18cf87bb506" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ShareBasedCompensationArrangementByShareBasedPaymentAwardsContingentConsiderationSharesPerPhase_4b9f0fad-0eae-4deb-ba76-a00e37157ad3" xlink:href="cmpo-20231231.xsd#cmpo_ShareBasedCompensationArrangementByShareBasedPaymentAwardsContingentConsiderationSharesPerPhase"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_cmpo_ShareBasedCompensationArrangementByShareBasedPaymentAwardsContingentConsiderationSharesPerPhase_4b9f0fad-0eae-4deb-ba76-a00e37157ad3" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ShareBasedCompensationArrangementByShareBasedPaymentAwardsContingentConsiderationIntrinsicValue_67d3d732-90a3-44bd-8950-6e72f0870bb1" xlink:href="cmpo-20231231.xsd#cmpo_ShareBasedCompensationArrangementByShareBasedPaymentAwardsContingentConsiderationIntrinsicValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_cmpo_ShareBasedCompensationArrangementByShareBasedPaymentAwardsContingentConsiderationIntrinsicValue_67d3d732-90a3-44bd-8950-6e72f0870bb1" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue_858cd3e4-141b-46b3-be91-72bff44534c6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue_858cd3e4-141b-46b3-be91-72bff44534c6" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_97eaa6db-9a28-4f83-8167-7e866410d84b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_97eaa6db-9a28-4f83-8167-7e866410d84b" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_e0027a8c-93c2-43e9-bdb6-4ce33f0de9f4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_e0027a8c-93c2-43e9-bdb6-4ce33f0de9f4" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_8c4db53a-d798-4541-b8e9-e2ab764ba38e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_8c4db53a-d798-4541-b8e9-e2ab764ba38e" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_ba9b0180-c68b-42e1-965e-cc729770f418" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_ba9b0180-c68b-42e1-965e-cc729770f418" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_a0a97cf4-c177-4e19-b45d-3dca80213ee1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_a0a97cf4-c177-4e19-b45d-3dca80213ee1" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsProfitsInterestHurdle_9cf5a7fa-4cc5-4460-9ecb-8f270ed9a962" xlink:href="cmpo-20231231.xsd#cmpo_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsProfitsInterestHurdle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_cmpo_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsProfitsInterestHurdle_9cf5a7fa-4cc5-4460-9ecb-8f270ed9a962" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_f17e1513-0c96-443a-bcba-a0021740d8a4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_826dc5bf-cde0-4abd-b5cd-11f591576fb9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_f17e1513-0c96-443a-bcba-a0021740d8a4" xlink:type="arc" order="26"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/EQUITYCOMPENSATIONRSUPSUandEarnoutsActivityDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#EQUITYCOMPENSATIONRSUPSUandEarnoutsActivityDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/EQUITYCOMPENSATIONRSUPSUandEarnoutsActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_eea66ed0-4456-4533-9a13-3a44e056c593" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_cc8e4f2a-abad-4df3-b10d-69b5fd4687b7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_eea66ed0-4456-4533-9a13-3a44e056c593" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_cc8e4f2a-abad-4df3-b10d-69b5fd4687b7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_7159353b-b426-40e4-ab72-236a0212d91c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_cc8e4f2a-abad-4df3-b10d-69b5fd4687b7" xlink:to="loc_us-gaap_AwardTypeAxis_7159353b-b426-40e4-ab72-236a0212d91c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7159353b-b426-40e4-ab72-236a0212d91c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_7159353b-b426-40e4-ab72-236a0212d91c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7159353b-b426-40e4-ab72-236a0212d91c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_161d517c-b4bf-4c37-b6ed-7a82eeb30261" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_7159353b-b426-40e4-ab72-236a0212d91c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_161d517c-b4bf-4c37-b6ed-7a82eeb30261" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_99f6e901-62b0-40b9-9a7a-944e7c6c70b2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_161d517c-b4bf-4c37-b6ed-7a82eeb30261" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_99f6e901-62b0-40b9-9a7a-944e7c6c70b2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_aaaf0612-8403-48a5-ae6a-e2a0dbe480ad" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_161d517c-b4bf-4c37-b6ed-7a82eeb30261" xlink:to="loc_us-gaap_PerformanceSharesMember_aaaf0612-8403-48a5-ae6a-e2a0dbe480ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_EarnoutConsiderationMember_d4bc0b16-1b10-42d4-84c0-fd6cba88d4b4" xlink:href="cmpo-20231231.xsd#cmpo_EarnoutConsiderationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_161d517c-b4bf-4c37-b6ed-7a82eeb30261" xlink:to="loc_cmpo_EarnoutConsiderationMember_d4bc0b16-1b10-42d4-84c0-fd6cba88d4b4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfSharesRollForward_025f5411-19cc-4427-8fba-fbc40c036ab5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfSharesRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_eea66ed0-4456-4533-9a13-3a44e056c593" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfSharesRollForward_025f5411-19cc-4427-8fba-fbc40c036ab5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_bba01688-cce8-4910-9f66-9f5c19c0b873" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfSharesRollForward_025f5411-19cc-4427-8fba-fbc40c036ab5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_bba01688-cce8-4910-9f66-9f5c19c0b873" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_3a609a42-c845-4e12-b258-eef5846a297c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfSharesRollForward_025f5411-19cc-4427-8fba-fbc40c036ab5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_3a609a42-c845-4e12-b258-eef5846a297c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_04988b09-b2f5-417b-9ab0-26b461966c43" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfSharesRollForward_025f5411-19cc-4427-8fba-fbc40c036ab5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_04988b09-b2f5-417b-9ab0-26b461966c43" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_09b6b9a4-0960-4d77-bb90-82bac7351849" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfSharesRollForward_025f5411-19cc-4427-8fba-fbc40c036ab5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_09b6b9a4-0960-4d77-bb90-82bac7351849" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_e7acb1c9-d368-4803-aa1f-55f2e425a35e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/EQUITYCOMPENSATIONAssumptionsforEarnoutConsiderationDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#EQUITYCOMPENSATIONAssumptionsforEarnoutConsiderationDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/EQUITYCOMPENSATIONAssumptionsforEarnoutConsiderationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_7a6da3c7-4232-4abe-8fa1-ebb8ae4d2223" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_bc353db8-c396-457c-922c-f2dc5dd17931" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_7a6da3c7-4232-4abe-8fa1-ebb8ae4d2223" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_bc353db8-c396-457c-922c-f2dc5dd17931" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_01221b1a-e44a-4a8a-bda3-4a54d4097e4a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_bc353db8-c396-457c-922c-f2dc5dd17931" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_01221b1a-e44a-4a8a-bda3-4a54d4097e4a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_01221b1a-e44a-4a8a-bda3-4a54d4097e4a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_01221b1a-e44a-4a8a-bda3-4a54d4097e4a" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_01221b1a-e44a-4a8a-bda3-4a54d4097e4a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_a284b1bf-1c67-428d-8f32-97ab75fd913e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_01221b1a-e44a-4a8a-bda3-4a54d4097e4a" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_a284b1bf-1c67-428d-8f32-97ab75fd913e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputSharePriceMember_13191cea-5c43-4cc0-9ba9-649f07c9073d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputSharePriceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_a284b1bf-1c67-428d-8f32-97ab75fd913e" xlink:to="loc_us-gaap_MeasurementInputSharePriceMember_13191cea-5c43-4cc0-9ba9-649f07c9073d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputRiskFreeInterestRateMember_df366a11-28ef-41ca-8dc1-a33b5bf9c235" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputRiskFreeInterestRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_a284b1bf-1c67-428d-8f32-97ab75fd913e" xlink:to="loc_us-gaap_MeasurementInputRiskFreeInterestRateMember_df366a11-28ef-41ca-8dc1-a33b5bf9c235" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputPriceVolatilityMember_815036ca-50c1-4022-bac4-4c2fa77a0928" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputPriceVolatilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_a284b1bf-1c67-428d-8f32-97ab75fd913e" xlink:to="loc_us-gaap_MeasurementInputPriceVolatilityMember_815036ca-50c1-4022-bac4-4c2fa77a0928" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputExpectedDividendRateMember_54eb9030-673f-426e-8f8b-1aae6f5ba7ef" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputExpectedDividendRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_a284b1bf-1c67-428d-8f32-97ab75fd913e" xlink:to="loc_us-gaap_MeasurementInputExpectedDividendRateMember_54eb9030-673f-426e-8f8b-1aae6f5ba7ef" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_MeasurementInputExpectedForfeitureRateMember_ab322a47-7cc0-4f23-8248-7c268be5203e" xlink:href="cmpo-20231231.xsd#cmpo_MeasurementInputExpectedForfeitureRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_a284b1bf-1c67-428d-8f32-97ab75fd913e" xlink:to="loc_cmpo_MeasurementInputExpectedForfeitureRateMember_ab322a47-7cc0-4f23-8248-7c268be5203e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputExpectedTermMember_39d98bb5-5372-4ab8-ae17-14993424ae1d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputExpectedTermMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_a284b1bf-1c67-428d-8f32-97ab75fd913e" xlink:to="loc_us-gaap_MeasurementInputExpectedTermMember_39d98bb5-5372-4ab8-ae17-14993424ae1d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_8030ae7e-4364-46c3-a628-9b8480e57ee6" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_bc353db8-c396-457c-922c-f2dc5dd17931" xlink:to="loc_srt_RangeAxis_8030ae7e-4364-46c3-a628-9b8480e57ee6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_8030ae7e-4364-46c3-a628-9b8480e57ee6_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_8030ae7e-4364-46c3-a628-9b8480e57ee6" xlink:to="loc_srt_RangeMember_8030ae7e-4364-46c3-a628-9b8480e57ee6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_ea8b09e1-217b-49cf-b6b5-1d4a89610f64" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_8030ae7e-4364-46c3-a628-9b8480e57ee6" xlink:to="loc_srt_RangeMember_ea8b09e1-217b-49cf-b6b5-1d4a89610f64" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_df1e7b70-8621-4f91-b9af-e7c84ca8414b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_ea8b09e1-217b-49cf-b6b5-1d4a89610f64" xlink:to="loc_srt_MinimumMember_df1e7b70-8621-4f91-b9af-e7c84ca8414b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_f35ec72f-9fc5-4ade-96bd-b5d140338187" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_ea8b09e1-217b-49cf-b6b5-1d4a89610f64" xlink:to="loc_srt_MaximumMember_f35ec72f-9fc5-4ade-96bd-b5d140338187" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DerivativeInstrumentContingentConsiderationLiabilityMeasurementInput_f64b6690-8881-4798-bc54-e329dae1e502" xlink:href="cmpo-20231231.xsd#cmpo_DerivativeInstrumentContingentConsiderationLiabilityMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_7a6da3c7-4232-4abe-8fa1-ebb8ae4d2223" xlink:to="loc_cmpo_DerivativeInstrumentContingentConsiderationLiabilityMeasurementInput_f64b6690-8881-4798-bc54-e329dae1e502" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/RETIREMENTPLANDefinedContributionPlanDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#RETIREMENTPLANDefinedContributionPlanDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/RETIREMENTPLANDefinedContributionPlanDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedContributionPlanDisclosureLineItems_2b23f1f6-ded9-48cb-a2e7-c2f971907ad2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedContributionPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedContributionPlanTable_8cd38030-c0e8-4977-834f-a4389a9d7b34" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedContributionPlanTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedContributionPlanDisclosureLineItems_2b23f1f6-ded9-48cb-a2e7-c2f971907ad2" xlink:to="loc_us-gaap_DefinedContributionPlanTable_8cd38030-c0e8-4977-834f-a4389a9d7b34" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DefinedContributionPlanMatchingScenarioAxis_b06ba1fc-f9f2-4f3d-a93d-8da5539e42bd" xlink:href="cmpo-20231231.xsd#cmpo_DefinedContributionPlanMatchingScenarioAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DefinedContributionPlanTable_8cd38030-c0e8-4977-834f-a4389a9d7b34" xlink:to="loc_cmpo_DefinedContributionPlanMatchingScenarioAxis_b06ba1fc-f9f2-4f3d-a93d-8da5539e42bd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DefinedContributionPlanMatchingScenarioDomain_b06ba1fc-f9f2-4f3d-a93d-8da5539e42bd_default" xlink:href="cmpo-20231231.xsd#cmpo_DefinedContributionPlanMatchingScenarioDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_cmpo_DefinedContributionPlanMatchingScenarioAxis_b06ba1fc-f9f2-4f3d-a93d-8da5539e42bd" xlink:to="loc_cmpo_DefinedContributionPlanMatchingScenarioDomain_b06ba1fc-f9f2-4f3d-a93d-8da5539e42bd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DefinedContributionPlanMatchingScenarioDomain_53dbb22a-7d80-40f7-a2dd-86a7f75536d6" xlink:href="cmpo-20231231.xsd#cmpo_DefinedContributionPlanMatchingScenarioDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_cmpo_DefinedContributionPlanMatchingScenarioAxis_b06ba1fc-f9f2-4f3d-a93d-8da5539e42bd" xlink:to="loc_cmpo_DefinedContributionPlanMatchingScenarioDomain_53dbb22a-7d80-40f7-a2dd-86a7f75536d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DefinedContributionPlanMatchingScenarioOneMember_a9dda2e5-5bf2-4e47-a733-937cbea9d655" xlink:href="cmpo-20231231.xsd#cmpo_DefinedContributionPlanMatchingScenarioOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_DefinedContributionPlanMatchingScenarioDomain_53dbb22a-7d80-40f7-a2dd-86a7f75536d6" xlink:to="loc_cmpo_DefinedContributionPlanMatchingScenarioOneMember_a9dda2e5-5bf2-4e47-a733-937cbea9d655" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DefinedContributionPlanMatchingScenarioTwoMember_15eedc3a-0b73-4503-a58d-3a4876d24ced" xlink:href="cmpo-20231231.xsd#cmpo_DefinedContributionPlanMatchingScenarioTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cmpo_DefinedContributionPlanMatchingScenarioDomain_53dbb22a-7d80-40f7-a2dd-86a7f75536d6" xlink:to="loc_cmpo_DefinedContributionPlanMatchingScenarioTwoMember_15eedc3a-0b73-4503-a58d-3a4876d24ced" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DefinedContributionPlanRequisiteServicePeriod_854c05ea-4ce6-4a46-a728-4dd171b20531" xlink:href="cmpo-20231231.xsd#cmpo_DefinedContributionPlanRequisiteServicePeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedContributionPlanDisclosureLineItems_2b23f1f6-ded9-48cb-a2e7-c2f971907ad2" xlink:to="loc_cmpo_DefinedContributionPlanRequisiteServicePeriod_854c05ea-4ce6-4a46-a728-4dd171b20531" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch_e0e73810-a727-405b-a15a-8045bc271c02" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedContributionPlanDisclosureLineItems_2b23f1f6-ded9-48cb-a2e7-c2f971907ad2" xlink:to="loc_us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch_e0e73810-a727-405b-a15a-8045bc271c02" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent_46d449bb-c6d2-49c1-949b-4b282351b547" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedContributionPlanDisclosureLineItems_2b23f1f6-ded9-48cb-a2e7-c2f971907ad2" xlink:to="loc_us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent_46d449bb-c6d2-49c1-949b-4b282351b547" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedContributionPlanCostRecognized_62bdd4dd-15bb-453f-a2eb-d9fd54aba6ac" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedContributionPlanCostRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedContributionPlanDisclosureLineItems_2b23f1f6-ded9-48cb-a2e7-c2f971907ad2" xlink:to="loc_us-gaap_DefinedContributionPlanCostRecognized_62bdd4dd-15bb-453f-a2eb-d9fd54aba6ac" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/FAIRVALUEMEASUREMENTSFinancialAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#FAIRVALUEMEASUREMENTSFinancialAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/FAIRVALUEMEASUREMENTSFinancialAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_21687659-e02f-4c60-9b04-0871038c7130" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_99acf8a1-6dbb-413e-aad4-7b8802817a07" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_21687659-e02f-4c60-9b04-0871038c7130" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_99acf8a1-6dbb-413e-aad4-7b8802817a07" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4f229b31-93c1-4288-8ffd-0f23924db343" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_99acf8a1-6dbb-413e-aad4-7b8802817a07" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4f229b31-93c1-4288-8ffd-0f23924db343" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4f229b31-93c1-4288-8ffd-0f23924db343_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4f229b31-93c1-4288-8ffd-0f23924db343" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4f229b31-93c1-4288-8ffd-0f23924db343_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_13673da1-f2fe-4ffb-8692-51a9b0ff318d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4f229b31-93c1-4288-8ffd-0f23924db343" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_13673da1-f2fe-4ffb-8692-51a9b0ff318d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_7a78b1a7-f840-4c9f-a9a1-cc2674ea09c8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_13673da1-f2fe-4ffb-8692-51a9b0ff318d" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_7a78b1a7-f840-4c9f-a9a1-cc2674ea09c8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_28221b67-590a-432e-b8e4-c2c6f9416c28" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_13673da1-f2fe-4ffb-8692-51a9b0ff318d" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_28221b67-590a-432e-b8e4-c2c6f9416c28" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_2dbc16bd-d454-4d29-b80b-eee2f092fcb1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_13673da1-f2fe-4ffb-8692-51a9b0ff318d" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_2dbc16bd-d454-4d29-b80b-eee2f092fcb1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightAxis_cc328b38-d942-49ae-ab1b-a99ba576f2ba" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_99acf8a1-6dbb-413e-aad4-7b8802817a07" xlink:to="loc_us-gaap_ClassOfWarrantOrRightAxis_cc328b38-d942-49ae-ab1b-a99ba576f2ba" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_cc328b38-d942-49ae-ab1b-a99ba576f2ba_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_cc328b38-d942-49ae-ab1b-a99ba576f2ba" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_cc328b38-d942-49ae-ab1b-a99ba576f2ba_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_b468dcab-37e1-4d38-b822-8aadfac9283f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_cc328b38-d942-49ae-ab1b-a99ba576f2ba" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_b468dcab-37e1-4d38-b822-8aadfac9283f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_PublicWarrantsMember_2d769d0f-3caf-479f-b457-6bc248b4a39b" xlink:href="cmpo-20231231.xsd#cmpo_PublicWarrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_b468dcab-37e1-4d38-b822-8aadfac9283f" xlink:to="loc_cmpo_PublicWarrantsMember_2d769d0f-3caf-479f-b457-6bc248b4a39b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_PrivateWarrantsMember_68677b91-536b-45fc-b5a1-ff825471333e" xlink:href="cmpo-20231231.xsd#cmpo_PrivateWarrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_b468dcab-37e1-4d38-b822-8aadfac9283f" xlink:to="loc_cmpo_PrivateWarrantsMember_68677b91-536b-45fc-b5a1-ff825471333e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_26c8b7ca-1a77-4d27-a28a-e1ad0e5558ed" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_21687659-e02f-4c60-9b04-0871038c7130" xlink:to="loc_us-gaap_DerivativeAssets_26c8b7ca-1a77-4d27-a28a-e1ad0e5558ed" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstanding_f2c879d1-6d7a-46b2-8cc3-376835d41f5d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WarrantsAndRightsOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_21687659-e02f-4c60-9b04-0871038c7130" xlink:to="loc_us-gaap_WarrantsAndRightsOutstanding_f2c879d1-6d7a-46b2-8cc3-376835d41f5d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DerivativeInstrumentContingentConsiderationLiability_fe9efc15-c2d6-4e57-b0d8-dee498cc4cf8" xlink:href="cmpo-20231231.xsd#cmpo_DerivativeInstrumentContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_21687659-e02f-4c60-9b04-0871038c7130" xlink:to="loc_cmpo_DerivativeInstrumentContingentConsiderationLiability_fe9efc15-c2d6-4e57-b0d8-dee498cc4cf8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability_49933f3d-4304-4660-9431-c6836b18498a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_21687659-e02f-4c60-9b04-0871038c7130" xlink:to="loc_us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability_49933f3d-4304-4660-9431-c6836b18498a" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/FAIRVALUEMEASUREMENTSFairValueAssumptionsDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#FAIRVALUEMEASUREMENTSFairValueAssumptionsDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/FAIRVALUEMEASUREMENTSFairValueAssumptionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_fd152b26-c0ed-43a0-9cde-65f276132267" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_cfa96d43-13de-4fce-b979-3f724953b18a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_fd152b26-c0ed-43a0-9cde-65f276132267" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_cfa96d43-13de-4fce-b979-3f724953b18a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_3d4be269-f11f-4166-b692-722028b8bcbb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_cfa96d43-13de-4fce-b979-3f724953b18a" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_3d4be269-f11f-4166-b692-722028b8bcbb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_3d4be269-f11f-4166-b692-722028b8bcbb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_3d4be269-f11f-4166-b692-722028b8bcbb" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_3d4be269-f11f-4166-b692-722028b8bcbb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_095328ae-5bf5-4414-972a-7d60b5c512c6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_3d4be269-f11f-4166-b692-722028b8bcbb" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_095328ae-5bf5-4414-972a-7d60b5c512c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputRiskFreeInterestRateMember_b5c0c62e-09fd-4bba-8388-eb3409de2a35" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputRiskFreeInterestRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_095328ae-5bf5-4414-972a-7d60b5c512c6" xlink:to="loc_us-gaap_MeasurementInputRiskFreeInterestRateMember_b5c0c62e-09fd-4bba-8388-eb3409de2a35" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputPriceVolatilityMember_2594493a-eaa4-47f6-ae90-85964b8afc7b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputPriceVolatilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_095328ae-5bf5-4414-972a-7d60b5c512c6" xlink:to="loc_us-gaap_MeasurementInputPriceVolatilityMember_2594493a-eaa4-47f6-ae90-85964b8afc7b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputExpectedDividendRateMember_493b6747-c076-467e-99ec-06da9367f97f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputExpectedDividendRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_095328ae-5bf5-4414-972a-7d60b5c512c6" xlink:to="loc_us-gaap_MeasurementInputExpectedDividendRateMember_493b6747-c076-467e-99ec-06da9367f97f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputExpectedTermMember_c7477956-3fef-4960-9ec7-01fc95b2107f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputExpectedTermMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_095328ae-5bf5-4414-972a-7d60b5c512c6" xlink:to="loc_us-gaap_MeasurementInputExpectedTermMember_c7477956-3fef-4960-9ec7-01fc95b2107f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_488ef7c6-46e7-4d19-a9df-890983d0d2a5" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_cfa96d43-13de-4fce-b979-3f724953b18a" xlink:to="loc_srt_RangeAxis_488ef7c6-46e7-4d19-a9df-890983d0d2a5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_488ef7c6-46e7-4d19-a9df-890983d0d2a5_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_488ef7c6-46e7-4d19-a9df-890983d0d2a5" xlink:to="loc_srt_RangeMember_488ef7c6-46e7-4d19-a9df-890983d0d2a5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_17c083fb-130a-4a7b-8ff3-0b1a73d78792" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_488ef7c6-46e7-4d19-a9df-890983d0d2a5" xlink:to="loc_srt_RangeMember_17c083fb-130a-4a7b-8ff3-0b1a73d78792" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_e7196fd3-7953-44ef-8e31-4235992176f6" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_17c083fb-130a-4a7b-8ff3-0b1a73d78792" xlink:to="loc_srt_MinimumMember_e7196fd3-7953-44ef-8e31-4235992176f6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_4fdac758-7582-48e3-8e33-c1c7c275b080" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_17c083fb-130a-4a7b-8ff3-0b1a73d78792" xlink:to="loc_srt_MaximumMember_4fdac758-7582-48e3-8e33-c1c7c275b080" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharePrice_f6de20f2-0e57-47cc-850d-ef9fa13b1576" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_fd152b26-c0ed-43a0-9cde-65f276132267" xlink:to="loc_us-gaap_SharePrice_f6de20f2-0e57-47cc-850d-ef9fa13b1576" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_ReverseRecapitalizationContingentConsiderationMeasurementInput_34e8736e-7f8d-43ce-848e-89ecbf1dfa56" xlink:href="cmpo-20231231.xsd#cmpo_ReverseRecapitalizationContingentConsiderationMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_fd152b26-c0ed-43a0-9cde-65f276132267" xlink:to="loc_cmpo_ReverseRecapitalizationContingentConsiderationMeasurementInput_34e8736e-7f8d-43ce-848e-89ecbf1dfa56" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/GEOGRAPHICINFORMATIONANDCONCENTRATIONSGeographicalRevenueInformationDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#GEOGRAPHICINFORMATIONANDCONCENTRATIONSGeographicalRevenueInformationDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/GEOGRAPHICINFORMATIONANDCONCENTRATIONSGeographicalRevenueInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_1b5e02c2-88cc-4c9b-9c05-1bbeccc3eb22" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_75a88443-7cc1-444a-83cf-4fe02d2d1bfc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_1b5e02c2-88cc-4c9b-9c05-1bbeccc3eb22" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_75a88443-7cc1-444a-83cf-4fe02d2d1bfc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_2282228a-a437-4528-953f-630b0e101834" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_75a88443-7cc1-444a-83cf-4fe02d2d1bfc" xlink:to="loc_srt_StatementGeographicalAxis_2282228a-a437-4528-953f-630b0e101834" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_2282228a-a437-4528-953f-630b0e101834_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_2282228a-a437-4528-953f-630b0e101834" xlink:to="loc_srt_SegmentGeographicalDomain_2282228a-a437-4528-953f-630b0e101834_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_9b7dc01d-4c21-48e3-955a-312c70c20bd9" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_2282228a-a437-4528-953f-630b0e101834" xlink:to="loc_srt_SegmentGeographicalDomain_9b7dc01d-4c21-48e3-955a-312c70c20bd9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_cf3f54d1-020d-4d90-b7d3-6a21d0438414" xlink:href="https://xbrl.sec.gov/country/2023/country-2023.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_9b7dc01d-4c21-48e3-955a-312c70c20bd9" xlink:to="loc_country_US_cf3f54d1-020d-4d90-b7d3-6a21d0438414" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember_d4ce530c-b537-4f54-8d73-e10999edc02a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NonUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_9b7dc01d-4c21-48e3-955a-312c70c20bd9" xlink:to="loc_us-gaap_NonUsMember_d4ce530c-b537-4f54-8d73-e10999edc02a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_e02a3c98-2f49-4b43-8b96-7e2e53eca0b6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_1b5e02c2-88cc-4c9b-9c05-1bbeccc3eb22" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_e02a3c98-2f49-4b43-8b96-7e2e53eca0b6" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/GEOGRAPHICINFORMATIONANDCONCENTRATIONSNarrativeDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#GEOGRAPHICINFORMATIONANDCONCENTRATIONSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/GEOGRAPHICINFORMATIONANDCONCENTRATIONSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskLineItems_a2e5da7b-058f-4f33-a73a-48445bd29e27" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTable_8ff9473c-cedc-4498-88ef-4a79276e758e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_a2e5da7b-058f-4f33-a73a-48445bd29e27" xlink:to="loc_us-gaap_ConcentrationRiskTable_8ff9473c-cedc-4498-88ef-4a79276e758e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_a63d118f-70f9-4764-a65a-b29db875c156" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_8ff9473c-cedc-4498-88ef-4a79276e758e" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_a63d118f-70f9-4764-a65a-b29db875c156" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_a63d118f-70f9-4764-a65a-b29db875c156_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_a63d118f-70f9-4764-a65a-b29db875c156" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_a63d118f-70f9-4764-a65a-b29db875c156_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_fd3db25b-4647-4918-9424-56ff8327a1b4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_a63d118f-70f9-4764-a65a-b29db875c156" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_fd3db25b-4647-4918-9424-56ff8327a1b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_09803089-1555-485a-91d0-218c490d1d84" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_fd3db25b-4647-4918-9424-56ff8327a1b4" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_09803089-1555-485a-91d0-218c490d1d84" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableMember_c8e6a808-9b02-4838-a9d9-9c183093c2cb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_fd3db25b-4647-4918-9424-56ff8327a1b4" xlink:to="loc_us-gaap_AccountsReceivableMember_c8e6a808-9b02-4838-a9d9-9c183093c2cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsProductLineMember_bf33d975-f45d-4774-b4cd-f719d6bc1ffb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostOfGoodsProductLineMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_fd3db25b-4647-4918-9424-56ff8327a1b4" xlink:to="loc_us-gaap_CostOfGoodsProductLineMember_bf33d975-f45d-4774-b4cd-f719d6bc1ffb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_8c1a24bb-4e1c-43f5-a23b-9ed0dbbf8c19" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_8ff9473c-cedc-4498-88ef-4a79276e758e" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_8c1a24bb-4e1c-43f5-a23b-9ed0dbbf8c19" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_8c1a24bb-4e1c-43f5-a23b-9ed0dbbf8c19_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_8c1a24bb-4e1c-43f5-a23b-9ed0dbbf8c19" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_8c1a24bb-4e1c-43f5-a23b-9ed0dbbf8c19_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_02c2d7b5-f3b7-4fb5-9168-8e2a7fed29da" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_8c1a24bb-4e1c-43f5-a23b-9ed0dbbf8c19" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_02c2d7b5-f3b7-4fb5-9168-8e2a7fed29da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_5d3bd43c-3a21-4e79-93eb-aa23cdc7b208" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_02c2d7b5-f3b7-4fb5-9168-8e2a7fed29da" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_5d3bd43c-3a21-4e79-93eb-aa23cdc7b208" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplierConcentrationRiskMember_243e3339-7306-44c3-921d-7436f87158cb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SupplierConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_02c2d7b5-f3b7-4fb5-9168-8e2a7fed29da" xlink:to="loc_us-gaap_SupplierConcentrationRiskMember_243e3339-7306-44c3-921d-7436f87158cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_dd0c552e-31f2-4afe-938b-f6245c4fd760" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_8ff9473c-cedc-4498-88ef-4a79276e758e" xlink:to="loc_srt_MajorCustomersAxis_dd0c552e-31f2-4afe-938b-f6245c4fd760" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_dd0c552e-31f2-4afe-938b-f6245c4fd760_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_dd0c552e-31f2-4afe-938b-f6245c4fd760" xlink:to="loc_srt_NameOfMajorCustomerDomain_dd0c552e-31f2-4afe-938b-f6245c4fd760_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_5c818f6f-69ce-4052-bbaf-884147eee704" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_dd0c552e-31f2-4afe-938b-f6245c4fd760" xlink:to="loc_srt_NameOfMajorCustomerDomain_5c818f6f-69ce-4052-bbaf-884147eee704" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_TwoCustomersMember_709008e9-5a9f-4df8-b97f-bdc9d0e9c8ab" xlink:href="cmpo-20231231.xsd#cmpo_TwoCustomersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_5c818f6f-69ce-4052-bbaf-884147eee704" xlink:to="loc_cmpo_TwoCustomersMember_709008e9-5a9f-4df8-b97f-bdc9d0e9c8ab" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionBySupplierAxis_d8e5ebea-c310-4bbc-9add-6b984522afb9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionBySupplierAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_8ff9473c-cedc-4498-88ef-4a79276e758e" xlink:to="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionBySupplierAxis_d8e5ebea-c310-4bbc-9add-6b984522afb9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionSupplierDomain_d8e5ebea-c310-4bbc-9add-6b984522afb9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionSupplierDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionBySupplierAxis_d8e5ebea-c310-4bbc-9add-6b984522afb9" xlink:to="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionSupplierDomain_d8e5ebea-c310-4bbc-9add-6b984522afb9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionSupplierDomain_bdce6823-9fb7-4a1e-bcea-c3db8477fbff" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionSupplierDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionBySupplierAxis_d8e5ebea-c310-4bbc-9add-6b984522afb9" xlink:to="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionSupplierDomain_bdce6823-9fb7-4a1e-bcea-c3db8477fbff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_TwoSuppliersMember_d3fb3608-a7f6-48c0-a8a4-175c6de2598d" xlink:href="cmpo-20231231.xsd#cmpo_TwoSuppliersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionSupplierDomain_bdce6823-9fb7-4a1e-bcea-c3db8477fbff" xlink:to="loc_cmpo_TwoSuppliersMember_d3fb3608-a7f6-48c0-a8a4-175c6de2598d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_3822fa8a-6f93-4e75-8f89-602cfa0a45b0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_a2e5da7b-058f-4f33-a73a-48445bd29e27" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_3822fa8a-6f93-4e75-8f89-602cfa0a45b0" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/EARNINGSPERSHAREAntidilutiveSharesDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#EARNINGSPERSHAREAntidilutiveSharesDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/EARNINGSPERSHAREAntidilutiveSharesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_ef942050-736c-48f9-9200-5cebcca03863" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_af80258f-b8e9-4552-af30-09a5444cb316" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_ef942050-736c-48f9-9200-5cebcca03863" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_af80258f-b8e9-4552-af30-09a5444cb316" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_af67d4ea-eb10-459b-adf1-ac52387741d3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_af80258f-b8e9-4552-af30-09a5444cb316" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_af67d4ea-eb10-459b-adf1-ac52387741d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_af67d4ea-eb10-459b-adf1-ac52387741d3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_af67d4ea-eb10-459b-adf1-ac52387741d3" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_af67d4ea-eb10-459b-adf1-ac52387741d3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_4e2cd324-497d-4495-9447-2d65e5920cda" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_af67d4ea-eb10-459b-adf1-ac52387741d3" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_4e2cd324-497d-4495-9447-2d65e5920cda" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_146e7cae-c880-458c-8e60-fc81826a3294" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_4e2cd324-497d-4495-9447-2d65e5920cda" xlink:to="loc_us-gaap_WarrantMember_146e7cae-c880-458c-8e60-fc81826a3294" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_8d8a5dc0-74d0-496d-b77e-e0f63eb1afb8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_4e2cd324-497d-4495-9447-2d65e5920cda" xlink:to="loc_us-gaap_CommonClassBMember_8d8a5dc0-74d0-496d-b77e-e0f63eb1afb8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_EarnoutConsiderationMember_bcf94e85-a3f9-4a98-a16b-85cf99745345" xlink:href="cmpo-20231231.xsd#cmpo_EarnoutConsiderationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_4e2cd324-497d-4495-9447-2d65e5920cda" xlink:to="loc_cmpo_EarnoutConsiderationMember_bcf94e85-a3f9-4a98-a16b-85cf99745345" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockCompensationPlanMember_e0b06324-93b5-4592-91c2-57ec6190602c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockCompensationPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_4e2cd324-497d-4495-9447-2d65e5920cda" xlink:to="loc_us-gaap_StockCompensationPlanMember_e0b06324-93b5-4592-91c2-57ec6190602c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_ed0a1945-6d7e-46b2-84ea-67f35ba1d2d4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_ef942050-736c-48f9-9200-5cebcca03863" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_ed0a1945-6d7e-46b2-84ea-67f35ba1d2d4" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/EARNINGSPERSHAREImpactofChangeinAccountingPolicyDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#EARNINGSPERSHAREImpactofChangeinAccountingPolicyDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/EARNINGSPERSHAREImpactofChangeinAccountingPolicyDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_3bbfd362-f25e-45a1-92b2-ed1c0956dd2f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_7ae9e0dc-c667-4e8f-9b00-d4627fe64dbb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_3bbfd362-f25e-45a1-92b2-ed1c0956dd2f" xlink:to="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_7ae9e0dc-c667-4e8f-9b00-d4627fe64dbb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementAxis_f01fad45-a54e-457d-80ff-fd10c28bd239" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RestatementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_7ae9e0dc-c667-4e8f-9b00-d4627fe64dbb" xlink:to="loc_srt_RestatementAxis_f01fad45-a54e-457d-80ff-fd10c28bd239" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementDomain_f01fad45-a54e-457d-80ff-fd10c28bd239_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RestatementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RestatementAxis_f01fad45-a54e-457d-80ff-fd10c28bd239" xlink:to="loc_srt_RestatementDomain_f01fad45-a54e-457d-80ff-fd10c28bd239_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementDomain_b7afcf5c-63e5-4bae-979a-61da62f17bc8" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RestatementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RestatementAxis_f01fad45-a54e-457d-80ff-fd10c28bd239" xlink:to="loc_srt_RestatementDomain_b7afcf5c-63e5-4bae-979a-61da62f17bc8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioPreviouslyReportedMember_c07fa530-1632-4ce0-a7b5-706c49f8b381" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ScenarioPreviouslyReportedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RestatementDomain_b7afcf5c-63e5-4bae-979a-61da62f17bc8" xlink:to="loc_srt_ScenarioPreviouslyReportedMember_c07fa530-1632-4ce0-a7b5-706c49f8b381" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RevisionOfPriorPeriodReclassificationAdjustmentMember_f14fd2fc-5429-4d25-8c6a-09fc75be3998" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RevisionOfPriorPeriodReclassificationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RestatementDomain_b7afcf5c-63e5-4bae-979a-61da62f17bc8" xlink:to="loc_srt_RevisionOfPriorPeriodReclassificationAdjustmentMember_f14fd2fc-5429-4d25-8c6a-09fc75be3998" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_0b04a95e-8924-4993-8e26-1ddd5be8399d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_3bbfd362-f25e-45a1-92b2-ed1c0956dd2f" xlink:to="loc_us-gaap_EarningsPerShareBasic_0b04a95e-8924-4993-8e26-1ddd5be8399d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_a119fd65-63fe-4362-803c-b9a3d6768834" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_3bbfd362-f25e-45a1-92b2-ed1c0956dd2f" xlink:to="loc_us-gaap_EarningsPerShareDiluted_a119fd65-63fe-4362-803c-b9a3d6768834" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_17738a55-ba44-426a-8137-1851e240b223" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_3bbfd362-f25e-45a1-92b2-ed1c0956dd2f" xlink:to="loc_us-gaap_NetIncomeLoss_17738a55-ba44-426a-8137-1851e240b223" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest_fbb714a4-50ce-4122-9682-db9b14e947b7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_3bbfd362-f25e-45a1-92b2-ed1c0956dd2f" xlink:to="loc_us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest_fbb714a4-50ce-4122-9682-db9b14e947b7" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/COMMITMENTSANDCONTINGENCIESDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#COMMITMENTSANDCONTINGENCIESDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/COMMITMENTSANDCONTINGENCIESDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_0af9d04d-9e6a-4780-ad20-4a1b009b2dc3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_86c56f80-4c96-4ee6-80cd-c7dfb91739db" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_0af9d04d-9e6a-4780-ad20-4a1b009b2dc3" xlink:to="loc_us-gaap_LossContingenciesTable_86c56f80-4c96-4ee6-80cd-c7dfb91739db" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_165c8830-4f28-4766-b59e-cb6b8571c51a" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_86c56f80-4c96-4ee6-80cd-c7dfb91739db" xlink:to="loc_srt_RangeAxis_165c8830-4f28-4766-b59e-cb6b8571c51a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_165c8830-4f28-4766-b59e-cb6b8571c51a_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_165c8830-4f28-4766-b59e-cb6b8571c51a" xlink:to="loc_srt_RangeMember_165c8830-4f28-4766-b59e-cb6b8571c51a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_0bf17bb8-6176-4a32-b226-e66cf6c5ce61" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_165c8830-4f28-4766-b59e-cb6b8571c51a" xlink:to="loc_srt_RangeMember_0bf17bb8-6176-4a32-b226-e66cf6c5ce61" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_89b98747-605a-4b51-b6ea-06b7c98b89ff" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_0bf17bb8-6176-4a32-b226-e66cf6c5ce61" xlink:to="loc_srt_MinimumMember_89b98747-605a-4b51-b6ea-06b7c98b89ff" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_98296442-b9d3-4f3a-83bf-c7fd2e366a29" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_0bf17bb8-6176-4a32-b226-e66cf6c5ce61" xlink:to="loc_srt_MaximumMember_98296442-b9d3-4f3a-83bf-c7fd2e366a29" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAxis_d411195a-1356-49dd-9ed3-7aaa4b6ad243" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_86c56f80-4c96-4ee6-80cd-c7dfb91739db" xlink:to="loc_us-gaap_RelatedPartyTransactionAxis_d411195a-1356-49dd-9ed3-7aaa4b6ad243" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_d411195a-1356-49dd-9ed3-7aaa4b6ad243_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_d411195a-1356-49dd-9ed3-7aaa4b6ad243" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_d411195a-1356-49dd-9ed3-7aaa4b6ad243_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_43f4175e-a045-44cb-98c4-6383b78daf97" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_d411195a-1356-49dd-9ed3-7aaa4b6ad243" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_43f4175e-a045-44cb-98c4-6383b78daf97" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_RelatedPartyPotentialCommissionsDueMember_b1dfc92b-559c-46f6-bb28-c8a10a43c217" xlink:href="cmpo-20231231.xsd#cmpo_RelatedPartyPotentialCommissionsDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_43f4175e-a045-44cb-98c4-6383b78daf97" xlink:to="loc_cmpo_RelatedPartyPotentialCommissionsDueMember_b1dfc92b-559c-46f6-bb28-c8a10a43c217" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyEstimateOfPossibleLoss_d8cd2031-6a7d-4d3d-a9b0-8a2df0a159a4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LossContingencyEstimateOfPossibleLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_0af9d04d-9e6a-4780-ad20-4a1b009b2dc3" xlink:to="loc_us-gaap_LossContingencyEstimateOfPossibleLoss_d8cd2031-6a7d-4d3d-a9b0-8a2df0a159a4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForLegalSettlements_8c5324ca-1678-422c-be1f-e669ff049fa3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsForLegalSettlements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_0af9d04d-9e6a-4780-ad20-4a1b009b2dc3" xlink:to="loc_us-gaap_PaymentsForLegalSettlements_8c5324ca-1678-422c-be1f-e669ff049fa3" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/RELATEDPARTYTRANSACTIONSDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#RELATEDPARTYTRANSACTIONSDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/RELATEDPARTYTRANSACTIONSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_cb0ff1b2-2375-4d9c-a36c-ac712c4a8ea1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_11733954-299b-42ac-976d-5b489984c663" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_cb0ff1b2-2375-4d9c-a36c-ac712c4a8ea1" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_11733954-299b-42ac-976d-5b489984c663" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_aa108f38-0d46-49e2-ae4c-e2d3bc757150" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_11733954-299b-42ac-976d-5b489984c663" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_aa108f38-0d46-49e2-ae4c-e2d3bc757150" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_aa108f38-0d46-49e2-ae4c-e2d3bc757150_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_aa108f38-0d46-49e2-ae4c-e2d3bc757150" xlink:to="loc_us-gaap_RelatedPartyDomain_aa108f38-0d46-49e2-ae4c-e2d3bc757150_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_8b278c78-0771-48d3-9c5d-18c986d58525" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_aa108f38-0d46-49e2-ae4c-e2d3bc757150" xlink:to="loc_us-gaap_RelatedPartyDomain_8b278c78-0771-48d3-9c5d-18c986d58525" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_c8ad8368-1e46-412d-af43-31c12156a5f6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_8b278c78-0771-48d3-9c5d-18c986d58525" xlink:to="loc_us-gaap_RelatedPartyMember_c8ad8368-1e46-412d-af43-31c12156a5f6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_037a78dc-3960-48d5-820c-88881ffcae34" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_11733954-299b-42ac-976d-5b489984c663" xlink:to="loc_srt_ConsolidatedEntitiesAxis_037a78dc-3960-48d5-820c-88881ffcae34" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_037a78dc-3960-48d5-820c-88881ffcae34_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_037a78dc-3960-48d5-820c-88881ffcae34" xlink:to="loc_srt_ConsolidatedEntitiesDomain_037a78dc-3960-48d5-820c-88881ffcae34_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_7dfde933-eadf-4f7a-8311-2d3dbb103078" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_037a78dc-3960-48d5-820c-88881ffcae34" xlink:to="loc_srt_ConsolidatedEntitiesDomain_7dfde933-eadf-4f7a-8311-2d3dbb103078" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ParentCompanyMember_3a6c5ef4-4c72-4964-bdce-9aabb513e366" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ParentCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7dfde933-eadf-4f7a-8311-2d3dbb103078" xlink:to="loc_srt_ParentCompanyMember_3a6c5ef4-4c72-4964-bdce-9aabb513e366" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AffiliatedEntityMember_6c81970b-08b6-4a18-a39b-33d97a3fc85b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_AffiliatedEntityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_7dfde933-eadf-4f7a-8311-2d3dbb103078" xlink:to="loc_srt_AffiliatedEntityMember_6c81970b-08b6-4a18-a39b-33d97a3fc85b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_d688e617-0422-499a-9763-5a8887478a22" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_cb0ff1b2-2375-4d9c-a36c-ac712c4a8ea1" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_d688e617-0422-499a-9763-5a8887478a22" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_5cc01b54-dd76-46bb-b5ef-391ac3ad43e5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_cb0ff1b2-2375-4d9c-a36c-ac712c4a8ea1" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent_5cc01b54-dd76-46bb-b5ef-391ac3ad43e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_PaymentOnTaxReceivableAgreementLiability_0caea9f7-0c1c-4ab9-b0a2-964822561bdc" xlink:href="cmpo-20231231.xsd#cmpo_PaymentOnTaxReceivableAgreementLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_cb0ff1b2-2375-4d9c-a36c-ac712c4a8ea1" xlink:to="loc_cmpo_PaymentOnTaxReceivableAgreementLiability_0caea9f7-0c1c-4ab9-b0a2-964822561bdc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTaxExpenseDueFromAffiliatesCurrent_6f516259-701a-4638-9e66-32d27f22e307" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTaxExpenseDueFromAffiliatesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_cb0ff1b2-2375-4d9c-a36c-ac712c4a8ea1" xlink:to="loc_us-gaap_RelatedPartyTaxExpenseDueFromAffiliatesCurrent_6f516259-701a-4638-9e66-32d27f22e307" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://composecure.com/role/SUBSEQUENTEVENTSDetails" xlink:type="simple" xlink:href="cmpo-20231231.xsd#SUBSEQUENTEVENTSDetails"/>
  <link:definitionLink xlink:role="http://composecure.com/role/SUBSEQUENTEVENTSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_59de794a-698a-47fa-8875-a7b90e456ee6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_2d0d7cc4-5372-4d21-a107-6be15ca3dbc5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_59de794a-698a-47fa-8875-a7b90e456ee6" xlink:to="loc_us-gaap_SubsequentEventTable_2d0d7cc4-5372-4d21-a107-6be15ca3dbc5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_9246ba71-659e-40e2-ae0f-5c2731173759" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_2d0d7cc4-5372-4d21-a107-6be15ca3dbc5" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_9246ba71-659e-40e2-ae0f-5c2731173759" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_9246ba71-659e-40e2-ae0f-5c2731173759_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_9246ba71-659e-40e2-ae0f-5c2731173759" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_9246ba71-659e-40e2-ae0f-5c2731173759_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_eb98a04d-7d99-49dd-afbb-13c1670b12f5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_9246ba71-659e-40e2-ae0f-5c2731173759" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_eb98a04d-7d99-49dd-afbb-13c1670b12f5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_d555960a-e568-41ac-b69a-df8f43275688" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_eb98a04d-7d99-49dd-afbb-13c1670b12f5" xlink:to="loc_us-gaap_SubsequentEventMember_d555960a-e568-41ac-b69a-df8f43275688" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_deb0ad55-d4fa-4f8a-8bcc-29c3cc60e5ff" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_2d0d7cc4-5372-4d21-a107-6be15ca3dbc5" xlink:to="loc_us-gaap_CreditFacilityAxis_deb0ad55-d4fa-4f8a-8bcc-29c3cc60e5ff" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_deb0ad55-d4fa-4f8a-8bcc-29c3cc60e5ff_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_deb0ad55-d4fa-4f8a-8bcc-29c3cc60e5ff" xlink:to="loc_us-gaap_CreditFacilityDomain_deb0ad55-d4fa-4f8a-8bcc-29c3cc60e5ff_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_6c71801e-0bee-4435-887a-93e3c2d66680" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_deb0ad55-d4fa-4f8a-8bcc-29c3cc60e5ff" xlink:to="loc_us-gaap_CreditFacilityDomain_6c71801e-0bee-4435-887a-93e3c2d66680" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_240919a6-c36b-446d-ab7b-75808cdb5e01" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_6c71801e-0bee-4435-887a-93e3c2d66680" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_240919a6-c36b-446d-ab7b-75808cdb5e01" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_7258b7ec-347e-42b5-aea1-1be7b23d263d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_2d0d7cc4-5372-4d21-a107-6be15ca3dbc5" xlink:to="loc_us-gaap_DebtInstrumentAxis_7258b7ec-347e-42b5-aea1-1be7b23d263d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_7258b7ec-347e-42b5-aea1-1be7b23d263d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_7258b7ec-347e-42b5-aea1-1be7b23d263d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_7258b7ec-347e-42b5-aea1-1be7b23d263d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_595e5f16-ce55-4458-8eda-f2defa6aae7f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_7258b7ec-347e-42b5-aea1-1be7b23d263d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_595e5f16-ce55-4458-8eda-f2defa6aae7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_AmendedCreditFacility2024Member_44dbd58b-b077-4308-9b5d-4d6d1430f89e" xlink:href="cmpo-20231231.xsd#cmpo_AmendedCreditFacility2024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_595e5f16-ce55-4458-8eda-f2defa6aae7f" xlink:to="loc_cmpo_AmendedCreditFacility2024Member_44dbd58b-b077-4308-9b5d-4d6d1430f89e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_f90f4876-1910-4cc9-b7eb-101b0529ae2d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_2d0d7cc4-5372-4d21-a107-6be15ca3dbc5" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_f90f4876-1910-4cc9-b7eb-101b0529ae2d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_f90f4876-1910-4cc9-b7eb-101b0529ae2d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_f90f4876-1910-4cc9-b7eb-101b0529ae2d" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_f90f4876-1910-4cc9-b7eb-101b0529ae2d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_bfb12c8f-e894-4286-8eb1-d3198e365534" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_f90f4876-1910-4cc9-b7eb-101b0529ae2d" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_bfb12c8f-e894-4286-8eb1-d3198e365534" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_30cf7183-e18d-4f5c-8b6f-2923fa219d82" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_bfb12c8f-e894-4286-8eb1-d3198e365534" xlink:to="loc_us-gaap_LineOfCreditMember_30cf7183-e18d-4f5c-8b6f-2923fa219d82" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cmpo_DebtInstrumentCovenantMaximumDebtAndEquityRepurchaseAmount_f141073a-b7e2-4f53-8fc5-7fa96a8aed5a" xlink:href="cmpo-20231231.xsd#cmpo_DebtInstrumentCovenantMaximumDebtAndEquityRepurchaseAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_59de794a-698a-47fa-8875-a7b90e456ee6" xlink:to="loc_cmpo_DebtInstrumentCovenantMaximumDebtAndEquityRepurchaseAmount_f141073a-b7e2-4f53-8fc5-7fa96a8aed5a" xlink:type="arc" order="0"/>
  </link:definitionLink>
</link:linkbase>
