See under scaup.
any of several diving ducks of the genus Aythya, especially A. marila (greater scaup), of the Northern Hemisphere, having a bluish-gray bill.
Origin of scaup
1665–75; by ellipsis from scaup duck, probably with Scots, N dial. scaup, scalp mussel bed (of uncertain origin)
Also called scaup duck.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
either of two diving ducks, Aythya marila (greater scaup) or A. affinis (lesser scaup), of Europe and America, having a black-and-white plumage in the maleAlso called (US): bluebill, broadbill
Word Origin for scaup
C16: Scot variant of scalp
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012