an·nex • v. / əˈneks; ˈaneks/ [tr.] (often be annexed) append or add as an extra or subordinate part, esp. to a document: the first ten amendments were annexed to the Constitution in 1791. ∎ add (territory) to one's own territory by appropriation: Moldova was annexed by the Soviet Union in 1940. ∎ inf. take for oneself; appropriate. ∎ archaic add or attach as a condition or consequence. • n. / ˈaneks; -iks/ (pl. -nex·es ) 1. a building joined to or associated with a main building, providing additional space or accommodations. 2. an addition to a document: an annex to the report. DERIVATIVES: an·nex·a·tion / ˌanekˈsāshən; ˌanik-/ n. an·nex·a·tion·ist n. & adj.