scaup duck

GNU Webster's 1913

1. n. (Zoöl.) any one of several species of northern ducks of the genus Aythya, or Fuligula. The adult males are, in large part, black. The three North American species are: the greater scaup duck (Aythya marila, var. nearctica), called also broadbill, bluebill, blackhead, flock duck, flocking fowl, and raft duck; the lesser scaup duck (A. affinis), called also little bluebill, river broadbill, and shuffler; the tufted, or ring-necked, scaup duck (A. collaris), called also black jack, ringneck, ringbill, ringbill shuffler, etc. See Illust. of Ring-necked duck, under Ring-necked. The common European scaup, or mussel, duck (A. marila), closely resembles the American variety.

WordNet 3.0

1. n. diving ducks of North America having a bluish-grey bill