domestic partner vs doer

domestic partner and doer both are nouns.

Word	Noun	Adjective	Verb	Adverb
domestic partner	Yes	No	No	No
doer	Yes	No	No	No

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

domestic partner: a person (not necessarily a spouse) with whom you cohabit and share a long-term sexual relationship
doer: a person who acts and gets things done

Other hypernyms of domestic partner include actor, worker.

domestic partner (noun)	doer (noun)
a person (not necessarily a spouse) with whom you cohabit and share a long-term sexual relationship	a person who acts and gets things done