| Noun | 1. | duck - small wild or domesticated web-footed broad-billed swimming bird usually having a depressed body and short legs Aythya, genus Aythya - canvasback; redhead; pochard; etc. Aythya marila, greater scaup - large scaup of North America having a greenish iridescence on the head of the male Aythya affinis, lake duck, lesser scaup, lesser scaup duck - common scaup of North America; males have purplish heads |