bull·head / ˈboŏlˌhed/ • n. 1. (also bullhead catfish) an American freshwater catfish (family Ictaluridae) with four pairs of barbels around the mouth, including the black bullhead (Ameiurus melas).2. a small, mainly freshwater Eurasian fish (genera Cottus and Taurulus) of the sculpin family, with a broad flattened head and spiny fins.3. (also bullhead lily) a North American water lily (Nuphar variegatum) with globular yellow flowers.

bullhead Freshwater catfish, originally found throughout e USA. Now farmed as food, it has been introduced in Europe and Hawaii. It has four pairs of fleshy mouth whiskers and a square tail. Length: to 24in (61cm); weight: to 8lb (3.6kg). Family Ictaluridae; species include yellow Ictalurus natalis and brown Ictalurus nebulosus.