endorser vs endorse

endorser is a noun but endorse is not a noun.

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

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

endorser (verb)	endorse (verb)
	sign as evidence of legal transfer
	be behind; approve of
	guarantee as meeting a certain standard
	give support or one's approval to