asseverator vs asserter

asseverator and asserter both are nouns.

Word	Noun	Adjective	Verb	Adverb
asseverator	Yes	No	No	No
asserter	Yes	No	No	No

As nouns, asseverator and asserter are synonyms defined as:

Other synonyms of asseverator include affirmer, avower, declarer.

asseverator (noun)	asserter (noun)
someone who claims to speak the truth	someone who claims to speak the truth