chatterer vs verbaliser

chatterer and verbaliser both are nouns.

Word	Noun	Adjective	Verb	Adverb
chatterer	Yes	No	No	No
verbaliser	Yes	No	No	No

As nouns, verbaliser is a hypernym of chatterer; that is, verbaliser is a word with a broader meaning than chatterer:

chatterer: an obnoxious and foolish and loquacious talker
verbaliser: someone who expresses in language; someone who talks (especially someone who delivers a public speech or someone especially garrulous)

Other hypernyms of chatterer include speaker, talker, utterer, verbalizer.

chatterer (noun)	verbaliser (noun)
passerine bird of New World tropics	someone who expresses in language; someone who talks (especially someone who delivers a public speech or someone especially garrulous)
an obnoxious and foolish and loquacious talker