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)
 

Shuffler \Shuf"fler\, n.

1. One who shuffles.

2. (Zo["o]l.) Either one of the three common American scaup ducks. See Scaup duck, under Scaup.

Source: Webster's Revised Unabridged Dictionary (1913)