"Eider" is a word in ENGLISH

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.