The Collaborative International Dictionary of English v.0.48:

Shorten \Short"en\, v. t. [imp. & p. p. Shortened ?; p. pr. &
   vb. n. Shortening.] [See Short, a.]
   1. To make short or shorter in measure, extent, or time; as,
      to shorten distance; to shorten a road; to shorten days of
      calamity.
      [1913 Webster]

   2. To reduce or diminish in amount, quantity, or extent; to
      lessen; to abridge; to curtail; to contract; as, to
      shorten work, an allowance of food, etc.
      [1913 Webster]

            Here, where the subject is so fruitful, I am
            shortened by my chain.                --Dryden.
      [1913 Webster]

   3. To make deficient (as to); to deprive; -- with of.
      [1913 Webster]

            Spoiled of his nose, and shortened of his ears.
                                                  --Dryden.
      [1913 Webster]

   4. To make short or friable, as pastry, with butter, lard,
      pot liquor, or the like.
      [1913 Webster]

   To shorten a rope (Naut.), to take in the slack of it.

   To shorten sail (Naut.), to reduce sail by taking it in.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Shorten \Short"en\, v. i.
   To become short or shorter; as, the day shortens in northern
   latitudes from June to December; a metallic rod shortens by
   cold.
   [1913 Webster]

The Free On-line Dictionary of Computing (17 December 2009):

Shorten

    A form of lossless audio
   compression.

   [Details?]

   (2001-12-17)


Moby Thesaurus II by Grady Ward, 1.0:

121 Moby Thesaurus words for "shorten":
   abate, abbreviate, abrade, abridge, abstract, bate, be telegraphic,
   bob, bobtail, boil down, brief, capsule, capsulize, circumscribe,
   clip, coarct, compact, compress, concentrate, condense,
   consolidate, constrict, constringe, contract, cramp, crop, curtail,
   cut, cut back, cut down, cut off short, cut short, damp, dampen,
   decrease, deduct, deflate, depreciate, depress, derogate, detract,
   digest, diminish, disparage, dock, downgrade, drain, draw, draw in,
   draw together, eat away, elide, epitomize, erode, excerpt, extract,
   file away, foreshorten, hem, impair, knit, leach, lessen, lower,
   minify, minimize, mow, narrow, nip, nutshell, outline, pare, poll,
   pollard, prune, pucker, pucker up, purify, purse, reap, recap,
   recapitulate, reduce, refine, remove, retrench, roll back,
   rub away, scale down, shave, shear, shrink, simplify, sketch,
   sketch out, slash, snub, solidify, step down, strangle,
   strangulate, stunt, subduct, subtract, sum up, summarize,
   synopsize, take away, take from, take in, telescope, thin,
   thin out, trim, truncate, tune down, waste no words, wear away,
   weed, withdraw, wrinkle