eiderdown
UK[ˈaɪ.də.daʊn]US[ˈaɪ.dɚ.daʊn]
n
the soft, fine feathers from the breast of the female eider duck, used for stuffing quilts and pillows.
n
a thick, warm quilt stuffed with this material or a similar soft substance.
Morpheme Breakdown
eider
down
eider
down
Etymology
the word 'eiderdown' is a transparent compound formed from the name of the bird and the substance it provides. 'eider' derives from icelandic/old norse 'æðr', referring specifically to the large sea duck known for its exceptionally soft and warm plumage. the second element, 'down', comes from old norse 'dúnn', meaning 'soft feathers' or 'fluff'. the term entered english in the late 18th century, directly naming the prized material—the breast feathers of the eider duck—and, by metonymy, the quilt filled with it. this compound perfectly illustrates how english can create precise terms by combining elements that literally describe the source and nature of an object.
Analysis
Structure: eider + down
eider: origin: icelandic, from old norse 'æðr' (eider duck). functional role: specifies the source animal.
down: origin: old norse 'dúnn' (soft feathers). functional role: specifies the material.
Examples
the pillow was filled with luxurious eiderdown, making it incredibly soft.
she pulled the eiderdown up to her chin to ward off the winter chill.
authentic eiderdown is highly valued for its superior insulation and lightness.