Blackfish \Black"fish\, n. 1. (Zool.) A small kind of whale, of the genus {Globicephalus}, of several species. The most common is {Globicephalus melas}. Also sometimes applied to other whales of larger size. [1913 Webster] 2. (Zool.) The tautog of New England ({Tautoga}). [1913 Webster] 3. (Zool.) The black sea bass ({Centropristis atrarius}) of the Atlantic coast. It is excellent food fish; -- locally called also {black Harry}. [1913 Webster] 4. (Zool.) A fish of southern Europe ({Centrolophus pompilus}) of the Mackerel family. [1913 Webster] 5. (Zool.) The female salmon in the spawning season. [1913 Webster] Note: The name is locally applied to other fishes. [1913 Webster]