candidate vs doer

candidate and doer both are nouns.

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

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

candidate: someone who is considered for something (for an office or prize or honor etc.)
doer: a person who acts and gets things done

Other hypernyms of candidate include actor, worker.

candidate (noun)	doer (noun)
someone who is considered for something (for an office or prize or honor etc.)	a person who acts and gets things done
a politician who is running for public office