pl. -·ducks· or -·duck·
any of a genus (Tadorna) of brightly colored wild ducks that feed on fish, shellfish, etc. and nest in burrows
Any of various large waterfowl of the genus Tadorna of the Eastern Hemisphere, especially the Eurasian species T. tadorna, having black, white, and brownish-red plumage. Also called sheldrake.
Origin of shelduckshel(drake) + duck1.
(plural shelducks or shelduck)