coot

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of several waterbirds of the widely distributed genus Fulica, having dark-gray plumage, a black head and neck, and a white bill.
• noun Derogatory An eccentric or crotchety person, especially an old man.

from The Century Dictionary.

• noun A lobiped grallatorial and natatorial bird, of the genus Fulica and family Rallidæ, having the toes broadly lobate, the culmen of the bill extended on the front as a boss or casque, short wings, a very short, cocked-up tail, or bobtail, and thick and duck-like plumage on the under surface of the body.
• noun The foolish guillemot, Lomviatroile.
• noun A scoter; one of the large black sea-ducks of the genera (Edemia, Pelionetta, and Melanetta.
• noun A simpleton; a silly fellow.

from the GNU version of the Collaborative International Dictionary of English.

• noun A wading bird with lobate toes, of the genus Fulica. The common European or bald coot is Fulica atra (see under bald); the American is Fulica Americana
• noun The surf duck or scoter. In the United States all the species of (Œdemia are called coots. See scoter.
• noun colloq. A stupid fellow; a simpleton.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Any of various aquatic birds of the genus Fulica that are mainly black with a prominent frontal shield on the forehead.
• noun colloquial A stupid fellow; a simpleton
• noun slang, with the A success; something excellent.
• noun slang Body louse.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun slate-black slow-flying birds somewhat resembling ducks