| Noun | 1. | fish genus - any of various genus of fish Clupeidae, family Clupeidae - herrings; shad; sardines; etc. Clupea harangus, herring - commercially important food fish of northern waters of both Atlantic and Pacific Atlantic herring, Clupea harengus harengus - important food fish; found in enormous shoals in the northern Atlantic Clupea harengus pallasii, Pacific herring - important food fish of the northern Pacific |