withholder vs doer

withholder and doer both are nouns.

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

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

Other hypernyms of withholder include actor, worker.

withholder (noun)	doer (noun)
a person who restrains or checks or holds back	a person who acts and gets things done
a person who refrains from granting