50 U.S.C. § 3075 - U.S. Code - Unannotated Title 50. War and National Defense § 3075. “Function” and “Department of Defense” defined

(a) As used in sections 3002, 3021, 3023, 3025, and 3073 of this title, the term “function” includes functions, powers, and duties.

(b) As used in this Act, the term “Department of Defense” shall be deemed to include the military departments of the Army, the Navy, and the Air Force, and all agencies created under title II of this Act.