eiderdown vs comforter

eiderdown and comforter both are nouns.

Word	Noun	Adjective	Verb	Adverb
eiderdown	Yes	No	No	No
comforter	Yes	No	No	No

As nouns, comforter is a hypernym of eiderdown; that is, comforter is a word with a broader meaning than eiderdown:

eiderdown: a soft quilt usually filled with the down of the eider
comforter: bedding made of two layers of cloth filled with stuffing and stitched together

Other hypernyms of eiderdown include comfort, puff, quilt.

eiderdown (noun)	comforter (noun)
down of the eider duck	bedding made of two layers of cloth filled with stuffing and stitched together
a soft quilt usually filled with the down of the eider	device used for an infant to suck or bite on
	a person who commiserates with someone who has had misfortune
	a person who reduces the intensity (e.g., of fears) and calms and pacifies