This Chairman of the Joint Chiefs of Staff manual, the US Department of Defense DOD Dictionary of Military and Associated Terms December 2020, sets forth standard US military and associated terminology to encompass the joint activity of the Armed Forces of the United States. These military and associated terms, together with their definitions, constitute approved Department of Defense (DOD) terminology for general use by all DOD components. This publication supplements standard English-language dictionaries and standardizes military and associated terminology to improve communication and mutual understanding within DOD with other US Government departments and agencies and among the United States and its allies. This publication applies to the Office of the Secretary of Defense, the Services, the Joint Staff (JS), combatant commands, DOD agencies, and all other DOD components. It is the primary terminology source when preparing correspondence, to include policy, strategy, doctrine, and planning documents.