10 U.S.C. § 101(a)(11) (2010) (Title 10—Chapter 1: Definitions)
(a) In general. The following definitions apply in this title:
(11) The term "Defense Agency" means an organizational entity of the Department of Defense—
(A) that is established by the Secretary of Defense under section 191 of this title [10 U.S.C. § 191] (or under the second sentence of section 125(d) of this title (as in effect before October 1, 1986)) to perform a supply or service activity common to more than one military department (other than such an entity that is designated by the Secretary as a Department of Defense Field Activity); or
(B) that is designated by the Secretary of Defense as a Defense Agency.