blackfish

noun pl. blackfish, blackfishes

1. ☆ any of a genus (Globicephala) of large, black, migratory dolphins; pilot whale
2. any of a number of dark marine fishes, as a sea bass or tautog
3. an edible Siberian or Alaskan freshwater fish (Dallia pectoralis) of the same order (Salmoniformes) as trout, pike, and salmon: reputed to revive after being frozen