cowfish noun5 •Any of genera Acanthostracion and Lactoria, of the boxfish family Ostraciidae. •A marine plectognath fish, Acanthostracion quadricornis and allied species, having two projections, like horns, in front. •A grampus (Grampus griseus), Risso's dolphin. •A common bottlenose dolphin of California, Tursiops truncatus gillii. •A common galaxias (Galaxias maculatus) formscowfishes