fiddler crab

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of various burrowing crabs of the genus Uca of coastal areas, the male of which has a greatly enlarged anterior claw.

Century Dictionary and Cyclopedia

1. n. A small crab of the genus Gelasimus, as G. vocans or G. pugilator; a calling-crab: so called from the waving or brandishing of the odd large claw, as if fiddling. They are useful for bait, and injurious by burrowing into and weakening levees and dams. See cut under Gelasimus.

Wiktionary

1. n. a genus of crab in which the male has one hugely enlarged claw (genus Uca).

GNU Webster's 1913

1. n. (Zoöl.) See Fiddler, n., 2.

WordNet 3.0

1. n. burrowing crab of American coastal regions having one claw much enlarged in the male