ethnic vs doer

ethnic and doer both are nouns.

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

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

Other hypernyms of ethnic include actor, worker.

ethnic (noun)	doer (noun)
a person who is a member of an ethnic group	a person who acts and gets things done

ethnic (adjective)	doer (adjective)
not acknowledging the God of Christianity and Judaism and Islam
denoting or deriving from or distinctive of the ways of living built up by a group of people