The Collaborative International Dictionary of English v.0.48:

Fiddler \Fid"dler\, n. [AS. fi[eth]elere.]
   1. One who plays on a fiddle or violin.
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   2. (Zool.) 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
      fiddler crab, calling crab, soldier crab, and
      fighting crab.
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   3. (Zool.) The common European sandpiper (Tringoides
      hypoleucus); -- so called because it continually
      oscillates its body.
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   Fiddler crab. (Zool.) See Fiddler, n., 2.
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The Collaborative International Dictionary of English v.0.48:

Fighting \Fight"ing\, a.
   1. Qualified for war; fit for battle.
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            An host of fighting men.              --2 Chron.
                                                  xxvi. 11.
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   2. Occupied in war; being the scene of a battle; as, a
      fighting field. --Pope.
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   A fighting chance, one dependent upon the issue of a
      struggle. [Colloq.]

   Fighting crab (Zool.), the fiddler crab.

   Fighting fish (Zool.), a remarkably pugnacious East Indian
      fish (Betta pugnax), reared by the Siamese for
      spectacular fish fights.
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