Whitefish :: Whitefish (n.) Any one of several species of Coregonus, a genus of excellent food fishes allied to the salmons. They inhabit the lakes of the colder parts of North America, Asia, and Europe. The largest and most important American species (C. clupeiformis) is abundant in the Great Lakes, and in other lakes farther north. Called also lake whitefish, and Oswego bass..