Source : Webster's Revised Unabridged Dictionary (1913)

Fiddler \Fid"dler\, n. [AS. fi?elere.]
   1. One who plays on a fiddle or violin.

   2. (Zo["o]l.) A burrowing crab of the genus {Gelasimus}, of
      many species. The male has one claw very much enlarged,
      and often holds it in a position similar to that in which
      a musician holds a fiddle, hence the name; -- called also
      {calling crab}, {soldier crab}, and {fighting crab}.

   3. (Zo["o]l.) The common European sandpiper ({Tringoides
      hypoleucus}); -- so called because it continually
      oscillates its body.

   {Fiddler crab}. (Zo["o]l.) See {Fiddler}, n., 2.

Source : WordNet®

fiddler
     n 1: a musician who plays the violin [syn: {violinist}]
     2: someone who manipulates in a nervous or unconscious manner
        [syn: {twiddler}]
     3: an unskilled person who tries to fix or mend [syn: {tinkerer}]