endorser vs ratifier

endorser and ratifier both are nouns.

Word	Noun	Adjective	Verb	Adverb
endorser	Yes	No	No	No
ratifier	Yes	No	No	No

As nouns, endorser and ratifier are synonyms defined as:

Other synonyms of endorser include indorser, subscriber.

endorser (noun)	ratifier (noun)
someone who expresses strong approval	someone who expresses strong approval
a person who transfers his ownership interest in something by signing a check or negotiable security