faddist vs doer

faddist and doer both are nouns.

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

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

Other hypernyms of faddist include actor, worker.

faddist (noun)	doer (noun)
a person who subscribes to a variety of fads	a person who acts and gets things done