stutterer vs utterer

stutterer and utterer both are nouns.

Word	Noun	Adjective	Verb	Adverb
stutterer	Yes	No	No	No
utterer	Yes	No	No	No

As nouns, utterer is a hypernym of stutterer; that is, utterer is a word with a broader meaning than stutterer:

stutterer: someone who speaks with involuntary pauses and repetitions
utterer: someone who expresses in language; someone who talks (especially someone who delivers a public speech or someone especially garrulous)

Other hypernyms of stutterer include speaker, talker, verbaliser, verbalizer.

stutterer (noun)	utterer (noun)
someone who speaks with involuntary pauses and repetitions	someone who expresses in language; someone who talks (especially someone who delivers a public speech or someone especially garrulous)
	someone who circulates forged banknotes or counterfeit coins
	an organism that can utter vocal sounds