eider (n.)youdaoicibaDictYouDict[eider 词源字典]
type of duck, 1743, from German Eider or Dutch eider, both from Old Norse æþar, genitive of æþr "duck," according to Watkins from a North Germanic root *athi-, from Proto-Germanic *ethi-, from PIE "probable root" *eti- "eider duck."[eider etymology, eider origin, 英语词源]