eider

American  

[ahy-der] / ˈaɪ dər /

noun

1. eider duck.

2. eiderdown.

---

eider British  

/ 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

---

Etymology

Origin of eider

1735–45; < Icelandic æthar (in 18th century spelled ædar ), genitive singular of æthur eider duck, in phrase ædar dūnn down of the eider duck; spelling eider < German or Swedish

Example Sentences

Annual surveys have begun to record steady increases in eider ducks, guillemots, herring gulls and lesser-backed gulls on and around the island, year on year.

From BBC • Nov. 13, 2025

Newell designed this ungainly Willy Wonka–esque apparatus over decades in a costly process of trial and error that faced—and ultimately overcame—several challenges, including protecting the mussels from turbulent seas and voracious eider ducks.

From Scientific American • May 7, 2022

Izembek Lagoon holds one of the world’s largest beds of eelgrass, a rich food source for Pacific brant geese, endangered Steller’s eider sea ducks and other migratory birds.

From Seattle Times • Mar. 16, 2022

During our time there, we saw swans and king eider ducks, sandhill cranes, sandpipers, pintailed ducks, spectacled eider and gulls everywhere.

From Washington Post • Apr. 7, 2016

The flowers were gone; the birds flocked in great clouds, and among them were eider and old squaw ducks that kept to the rivers and beaches except when they migrated south.

From "Julie of the Wolves" by Jean Craighead George