greyback
/ˈɡreɪbak/noun
1 US. Any of several wading birds; especially the (red) knot, Calidris canutus, in winter plumage. Now historical.
2 English regional and US. The (greater) scaup, Aythya marila. Now rare.
3 United States regional. A louse. Also figurative. Now archaic and historical.
4 US. More fully greyback whale. The grey whale, Eschrichtius robustus.
5 English regional. More fully greyback crow. The hooded crow, Corvus corone cornix. Compare grey crow. Now rare.
6A member of a military or police force whose uniform includes, or consists of, a grey coat; specifically (US informal ) a soldier of the Confederate army in the American Civil War (1861–5). Compare greycoat, grey. Now archaic and historical.
- Recorded earliest in attributive use..
7 US. A monetary note issued by the Confederacy during the American Civil War. Compare blueback, greenback. Now historical.
Origin
Early 19th century; earliest use found in Alexander Wilson (1766–1813), ornithologist and poet. From grey + back.