1. [v]  make short or shorter; "shorten the skirt"; "shorten the rope by a few inches"
2. [v]  edit by omitting or modifying parts considered indelicate; "bowdlerize a novel"
3. [v]  reduce in scope while retaining essential elements; "The manuscript must be shortened"
4. [v]  become short or shorter; "In winter, the days shorten"
5. [v]  make shorter than originally intended; reduce or retrench in length or duration; "He shortened his trip due to illness"

1. \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.
   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.
            Here, where the subject is so fruitful, I am
            shortened by my chain.                --Dryden.
   3. To make deficient (as to); to deprive; -- with of.
            Spoiled of his nose, and shortened of his ears.
                                                  --Dryden.
   4. To make short or friable, as pastry, with butter, lard,
      pot liquor, or the like.
   {To shorten a rope} (Naut.), to take in the slack of it.
   {To shorten sail} (Naut.), to reduce sail by taking it in.
   

2. \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.
   

A form of lossless audio compression.