Source : Webster's Revised Unabridged Dictionary (1913)

Trawl \Trawl\, v. i. [OF. trauler, troller, F. tr[^o]ter, to
   drag about, to stroll about; probably of Teutonic origin. Cf.
   {Troll}, v. t.]
   To take fish, or other marine animals, with a trawl.

Trawl \Trawl\, n.
   1. A fishing line, often extending a mile or more, having
      many short lines bearing hooks attached to it. It is used
      for catching cod, halibut, etc.; a boulter. [U. S. &
      Canada]

   2. A large bag net attached to a beam with iron frames at its
      ends, and dragged at the bottom of the sea, -- used in
      fishing, and in gathering forms of marine life from the
      sea bottom.

Source : WordNet®

trawl
     n 1: a long fishing line with many shorter lines and hooks
          attached to it (usually suspended between buoys) [syn: {trawl
          line}, {spiller}, {setline}, {trotline}]
     2: a conical fishnet dragged through the water at great depths
        [syn: {dragnet}, {trawl net}]

trawl
     v : fish with trawlers

Source : Free On-Line Dictionary of Computing

trawl
     
        To sift through large volumes of data (e.g. {Usenet} postings,
        FTP archives, or the {Jargon File}) looking for something of
        interest.
        [{Jargon File}]