bullheadPronunciation: /ˈbʊlhɛd/Definition of bullhead noun 1a small mainly freshwater Eurasian fish of the sculpin family, with a broad flattened head and spiny fins. Genera Cottus and Taurulus, family Cottidae: three species 2 (also bullhead catfish) an American freshwater catfish. Genus Ictalurus, family Ictaluridae: several species bullhead in other Oxford dictionaries Definition of bullhead in the US English dictionary