signer vs doer

signer and doer both are nouns.

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

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

Other hypernyms of signer include actor, worker.

signer (noun)	doer (noun)
someone who signs and is bound by a document	a person who acts and gets things done
someone who can use sign language to communicate