Source : Webster's Revised Unabridged Dictionary (1913)

Yahoo \Ya"hoo\, n.
   1. One of a race of filthy brutes in Swift's ``Gulliver's
      Travels.'' See in the Dictionary of Noted Names in
      Fiction.

   2. Hence, any brutish or vicious character.

   3. A raw countryman; a lout; a greenhorn. [U. S.]

Source : WordNet®

yahoo
     n 1: not very intelligent or interested in culture [syn: {yokel},
           {rube}, {hick}, {hayseed}, {bumpkin}, {chawbacon}]
     2: one of a race of brutes resembling men but subject to the
        Houyhnhnms in a novel by Jonathan Swift

Source : Free On-Line Dictionary of Computing

Yahoo
     
         Yet Another Hierarchical
        Officious/Obstreperous/Odiferous/Organized Oracle.
     
        (Or a member of a race of brutes in Swift's Gulliver's Travels
        who have the form and all the vices of man, or an uncouth or
        rowdy person).
     
        Probably the biggest hierarchical index of the {World-Wide
        Web}.  Originally at {Stanford University}, Yahoo moved to its
        own site in April 1995.  It allows you to move up and down the
        heirarchy, to search it and to suggest additions.  It also
        features "What's New", "What's Popular", "What's Cool" and a
        random link.
     
        {Home (http://www.yahoo.com/)}.
     
        (1995-04-05)