mentioner vs talker

mentioner and talker both are nouns.

Word	Noun	Adjective	Verb	Adverb
mentioner	Yes	No	No	No
talker	Yes	No	No	No

As nouns, talker is a hypernym of mentioner; that is, talker is a word with a broader meaning than mentioner:

mentioner: a speaker who refers to something briefly or incidentally
talker: someone who expresses in language; someone who talks (especially someone who delivers a public speech or someone especially garrulous)

Other hypernyms of mentioner include speaker, utterer, verbaliser, verbalizer.

mentioner (noun)	talker (noun)
a speaker who refers to something briefly or incidentally	someone who expresses in language; someone who talks (especially someone who delivers a public speech or someone especially garrulous)