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.
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            It is one thing to abbreviate by contracting,
            another by cutting off.               --Bacon.
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   2. (Math.) To reduce to lower terms, as a fraction.
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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.
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   2. (Biol.) Having one part relatively shorter than another or
      than the ordinary type.
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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'"