an·nex /ə-'neks, 'a-ˌneks/ vt
1: attach (2)
correspondence annex ed to the petition
a greenhouse annex ed to the building
2: to incorporate (as a territory) within a political domain
the district annex es only shards of 24 additional parishes — Hays v. Louisiana, 839 F. Supp. 1188 (1993)
an·nex·ation /ˌa-nek-'sā-shən/ n
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.