greyback

(noun) `Johnny' was applied as a nickname for Confederate soldiers by the Federal soldiers in the American Civil War; `greyback' derived from their grey Confederate uniforms. Synonyms: Rebel, Reb, Johnny Reb, Johnny.

(noun) a dowitcher with a grey back. Synonyms: grayback, Limnodromus griseus.

(noun) a sandpiper that breeds in the Arctic and winters in the southern hemisphere. Synonyms: knot, grayback, Calidris canutus.