2. (Zo["o]l.) A scaup duck. See below.

Scaup duck (Zo["o]l.), 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.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Broadbill \Broad"bill`\, n.

1. (Zo["o]l.) A wild duck (Aythya, or Fuligula, marila), which appears in large numbers on the eastern coast of the United States, in autumn; -- called also bluebill, blackhead, raft duck, and scaup duck. See Scaup duck.

2. (Zo["o]l.) The shoveler. See Shoveler.

Source: Webster's Revised Unabridged Dictionary (1913)