Merriam-Webster's Collegiate® Dictionary, 11th Edition
ANNEX
I. transitive verb
Etymology: Middle English, from Anglo-French annexer, from annexe attached, from Latin annexus, past participle of annectere to bind to, from ad- + nectere to bind
Date: 14th century
to attach as a quality, consequence, or condition, to join together materially ; unite , to add to something earlier, larger, or more important, to incorporate (a country or other territory) within the domain of a state, to obtain or take for oneself, annexation noun annexational adjective annexationist noun
II. noun
Date: 1501
something annexed as an expansion or supplement: as, an added stipulation or statement ; appendix , a subsidiary or supplementary building or structure ; wing