Source : Webster's Revised Unabridged Dictionary (1913)

Annex \An*nex"\, v. i.
   To join; to be united. --Tooke.

Annex \An*nex"\, n. [F. annexe, L. annexus, neut. annexum, p. p.
   of annectere.]
   Something annexed or appended; as, an additional stipulation
   to a writing, a subsidiary building to a main building; a
   wing.

Annex \An*nex"\, v. t. [imp. & p. p. {Annexed}; p. pr. & vb. n.
   {Annexing}.] [F. annexer, fr. L. annexus, p. p. of annectere
   to tie or bind to; ad + nectere to tie, to fasten together,
   akin to Skr. nah to bind.]
   1. To join or attach; usually to subjoin; to affix; to
      append; -- followed by to. ``He annexed a codicil to a
      will.'' --Johnson.

   2. To join or add, as a smaller thing to a greater.

            He annexed a province to his kingdom. --Johnson.

   3. To attach or connect, as a consequence, condition, etc.;
      as, to annex a penalty to a prohibition, or punishment to
      guilt.

   Syn: To add; append; affix; unite; coalesce. See {Add}.

Source : WordNet®

annex
     n : an addition that extends a main building [syn: {annexe}, {extension},
          {wing}]
     v 1: take illegally, as of territory; "The Israelis are annexing
          more and more territory on the West Bank"
     2: take (territory) by conquest; "Hitler annexed Lithuania"
     3: attach to