any of several large sea ducks of the genus Soamateria and allied genera of the Northern Hemisphere, the females of which yield eiderdown.
Origin
1850-55
Examples from the web for eider duck
Case report: epizootic of fowl cholera in the common eider duck.
The chicks are getting to an age where they may play with an eider duck wing or fish tail.
British Dictionary definitions for eider duck
eider
/ˈaɪdə/
noun
1.
any of several sea ducks of the genus Somateria, esp S. mollissima, and related genera, which occur in the N hemisphere. The male has black and white plumage, and the female is the source of eiderdown
Word Origin
C18: from Old Norse æthr; related to Swedish ejder, Dutch, German Eider