shelduck
Concise Oxford English Dictionary © 2008 Oxford University Press:
shelduck /ˈʃɛldʌk/
▶noun (pl. same or shelducks) a large goose-like duck with boldly marked plumage. [Tadorna tadorna and related species.]
– origin C18: prob. from dial. sheld ‘pied’ (rel. to MDu. schillede ‘variegated’) + duck1; the term sheldrake (sometimes used for the male) dates from ME.
'shelduck' also found in these Oxford entries:

