trout

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

• noun Any of various salmonid food and game fishes of the genera Oncorhynchus, Salmo, and Salvelinus, having a streamlined, speckled body and usually inhabiting freshwater streams or lakes. These genera also include the salmons and the chars.
• noun Any of various similar but unrelated fishes, such as the trout-perch.
• idiom (old trout) An elderly woman.

from The Century Dictionary.

• Same as troat.
• To fish for or catch trout.
• noun A fish of the family Salmonidæ, Salmo trutta, with blackish spots, common in the colder fresh waters of Europe, and highly esteemed as a food-fish and game-fish; any species of the same section of Salmo (see Salmo ); a river-salmon, salmon-trout, or lake-trout.
• noun A fish of the family Salmonidæ and genus Salvelinus (with its section Cristivomer), resembling those called in Europe char. See Salvelinus, and cuts under char and lake-trout, 2.
• noun Any fish of the family Galaxiidæ (which see).
• noun With a qualifying word, one of several fishes, not of the family Salmonidæ, resembling or suggesting a trout. See phrases below.
• noun One of several different trouts (not chars) of the western parts of North America, of the genus Salmo. See def. 1 .
• noun A weakfish or sea-trout, Cynoscion thalassinus.
• noun Salmo ferox of England.
• noun The black-bass, Micropterus salmoides.
• noun The Dolly Varden trout.
• noun The black-spotted trout, or mountain-trout of western North America.
• noun The Lake Tahoe trout.
• noun with black (see def. 1 )
• noun with red—a speckled trout (see def. 2).
• noun The weakfish or sea-trout Cynoscion maculatus.
• noun The bastard trout.

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

• noun (Zoöl.) Any one of numerous species of fishes belonging to Salmo, Salvelinus, and allied genera of the family Salmonidæ. They are highly esteemed as game fishes and for the quality of their flesh. All the species breed in fresh water, but after spawning many of them descend to the sea if they have an opportunity.
• noun (Zoöl.) Any one of several species of marine fishes more or less resembling a trout in appearance or habits, but not belonging to the same family, especially the California rock trouts, the common squeteague, and the southern, or spotted, squeteague; -- called also salt-water trout, sea trout, shad trout, and gray trout. See Squeteague, and Rock trout under Rock.
• noun (Zoöl.) a small fresh-water American fish (Percopsis guttatus), allied to the trout, but resembling a perch in its scales and mouth.

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

• noun Any of several species of fish in Salmonidae, closely related to salmon, and distinguished by spawning more than once.
• noun UK, pejorative An elderly woman of dubious sensibilities.
• verb To (figuratively) slap someone with a slimy, stinky, wet trout; to admonish jocularly.

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

• noun flesh of any of several primarily freshwater game and food fishes
• noun any of various game and food fishes of cool fresh waters mostly smaller than typical salmons