/blak"fish'/ , n. , pl. ( esp. collectively ) blackfish , ( esp. referring to two or more kinds or species ) blackfishes .
1. any of various dark-colored fishes, as the tautog, Tautoga onitis, or the sea bass, Centropristes striatus.
2. a small, freshwater food fish, Dallia pectoralis, found in Alaska and Siberia, noted for its ability to survive frozen in ice.
3. See black whale .
[ 1680-90, Amer.; BLACK + FISH ]