malcontent vs doer

malcontent and doer both are nouns.

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

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

Other hypernyms of malcontent include actor, worker.

malcontent (noun)	doer (noun)
a person who is discontented or disgusted	a person who acts and gets things done

malcontent (adjective)	doer (adjective)
discontented as toward authority