comforter vs bed clothing

comforter and bed clothing both are nouns.

Word	Noun	Adjective	Verb	Adverb
comforter	Yes	No	No	No
bed clothing	Yes	No	No	No

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

comforter: bedding made of two layers of cloth filled with stuffing and stitched together
bed clothing: coverings that are used on a bed

Other hypernyms of comforter include bedclothes, bedding.

comforter (noun)	bed clothing (noun)
bedding made of two layers of cloth filled with stuffing and stitched together	coverings that are used on a bed
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