moonfish

US: (mo̅o̅n′fish′)

WordReference Random House Unabridged Dictionary of American English © 2026

moon•fish  (mo̅o̅n′fish′), n., pl. (esp. collectively) -fish,  (esp. referring to two or more kinds or species) -fish•es. 

1. Fish Also called horsefish, horsehead. any of several silvery marine fishes of the genus Selene, having a very compressed body and inhabiting shallow coastal waters.
2. Fish the opah.
3. Fish any of various other rounded, silvery fishes.

• moon + fish 1640–50

Collins Concise English Dictionary © HarperCollins Publishers::

moonfish / ˈmuːnˌfɪʃ/ noun ( -fishes, -fish)

1. another name for opah