Any of various dark-coloured fish of the Old World, especially the rudderfish (). from 17th c.
A pilot whale, genus (occasionally also used for various other whales). from 17th c.
(North America) Either of two dark-coloured fish of the west Atlantic, the tautog of New England () and the black sea bass (). from 18th c.
(AU, NZ) Any of various dark-coloured fishes of Australasia, especially the luderick, , and a freshwater fish, . from 18th c.
1985, Peter Carey, Illywhacker, Faber and Faber 2003, p. 337:The creek was reputed to contain blackfish and Nathan … arranged the extraordinary collection of American lures he had inherited from an uncle.