The terminology used within the aerospace and defense (A&D) industry for product lifecycle management (PLM) concepts, processes, and artifacts is extensive and complex. When the A&D PLM Action Group (AD PAG) was founded in 2014 with the mission to identify and remediate common PLM-related pain points, one of the first problems that the members confronted was the communication barrier posed by inconsistent use of language. Over the years, AD PAG project teams have published reports and position papers on a range of topics. In this document, the AD PAG project teams have collaborated to create a comprehensive, common glossary that applies across all of their projects’ work products. This glossary of acronyms and terms draws from industry standard publications such as EIA-649, EIA-836, ATA Specification 2000, and the CIMdata PLM Glossary. This “living” document will continue to be updated to meet the needs of the AD PAG members and is published for the benefit of the aerospace and defense industry as a whole.