The Collaborative International Dictionary of English v.0.48:

Abbreviate \Ab*bre"vi*ate\ ([a^]b*br[=e]"v[i^]*[=a]t), v. t.
   [imp. & p. p. Abbreviated; p. pr. & vb. n. Abbreviating.]
   [L. abbreviatus, p. p. of abbreviare; ad + breviare to
   shorten, fr. brevis short. See Abridge.]
   1. To make briefer; to shorten; to abridge; to reduce by
      contraction or omission, especially of words written or
      spoken.
      [1913 Webster]

            It is one thing to abbreviate by contracting,
            another by cutting off.               --Bacon.
      [1913 Webster]

   2. (Math.) To reduce to lower terms, as a fraction.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Abbreviate \Ab*bre"vi*ate\ ([a^]b*br[=e]"v[i^]*[asl]t), a. [L.
   abbreviatus, p. p.]
   1. Abbreviated; abridged; shortened. [R.] "The abbreviate
      form." --Earle.
      [1913 Webster]

   2. (Biol.) Having one part relatively shorter than another or
      than the ordinary type.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Abbreviate \Ab*bre"vi*ate\, n.
   An abridgment. [Obs.] --Elyot.
   [1913 Webster]

WordNet (r) 3.0 (2006):

abbreviate
    v 1: reduce in scope while retaining essential elements; "The
         manuscript must be shortened" [syn: abridge,
         foreshorten, abbreviate, shorten, cut, contract,
         reduce] [ant: dilate, elaborate, enlarge, expand,
         expatiate, exposit, expound, flesh out,
         lucubrate]
    2: shorten; "Abbreviate `New York' and write `NY'"

Moby Thesaurus II by Grady Ward, 1.0:

88 Moby Thesaurus words for "abbreviate":
   abridge, abstract, attenuate, be telegraphic, blot out,
   blue-pencil, bob, boil down, bowdlerize, cancel, capsulize, censor,
   circumscribe, clip, coarct, compact, compress, concentrate,
   condense, consolidate, constrict, constringe, contract, cramp,
   crop, cross out, curtail, cut, cut back, cut down, cut off short,
   cut short, decrease, delete, dock, draw, draw in, draw together,
   edit, edit out, elide, epitomize, erase, expunge, expurgate,
   extenuate, foreshorten, kill, knit, mow, narrow, nip, omit, poll,
   pollard, prune, pucker, pucker up, purse, reap, recap,
   recapitulate, reduce, rescind, retrench, rub out, shave, shear,
   shorten, slash, snub, solidify, strangle, strangulate, strike,
   strike off, strike out, stunt, sum up, summarize, synopsize,
   take in, telescope, trim, truncate, void, waste no words,
   wrinkle