bedfellow vs doer

bedfellow and doer both are nouns.

Word	Noun	Adjective	Verb	Adverb
bedfellow	Yes	No	No	No
doer	Yes	No	No	No

As nouns, doer is a hypernym of bedfellow; that is, doer is a word with a broader meaning than bedfellow:

Other hypernyms of bedfellow include actor, worker.

bedfellow (noun)	doer (noun)
a person with whom you share a bed	a person who acts and gets things done
a temporary associate