attester vs attestant

attester and attestant both are nouns.

Word	Noun	Adjective	Verb	Adverb
attester	Yes	No	No	No
attestant	Yes	No	No	No

As nouns, attester and attestant are synonyms defined as:

attester and attestant: someone who affirms or vouches for the correctness or truth or genuineness of something

attester (noun)	attestant (noun)
someone who affirms or vouches for the correctness or truth or genuineness of something	(law) a person who attests to the genuineness of a document or signature by adding their own signature
	someone who affirms or vouches for the correctness or truth or genuineness of something