eider, n. [Of Scand. origin, cf. Icel ær; akin to Sw. eider, Dan. ederfugl.].
Eider down. [Cf. Icel. æ&edh;ardūn, Sw. eiderdūn, Dan. ederduun.] Down of the eider duck, much sought after as an article of luxury.
Any species of sea duck of the genus Somateria
, esp. Somateria mollissima
, which breeds in the northern parts of Europe and America, and lines its nest with fine down (taken from its own body) which is an article of commerce; -- called also eider duck
. The American eider (S. Dresseri
), the king eider (S. spectabilis
), and the spectacled eider (Arctonetta Fischeri
) are related species. [1913 Webster