rectifier vs doer

rectifier and doer both are nouns.

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

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

Other hypernyms of rectifier include actor, worker.

rectifier (noun)	doer (noun)
electrical device that transforms alternating into direct current	a person who acts and gets things done
a person who corrects or sets right