A large flatfish (Hippoglossus vulgaris), abundant in the northern seas, and much used for food. (Plural halibuts, also collectively halibut.)

Zoology. A flatfish having a spine with apophyses resembling the teeth of a comb. Obsolete. rare.

In American and Australasian use: One or other of various fishes belonging to related genera (esp. Achirus) or to the family Pleuronectidæ.