endorsement vs endorse

endorsement is a noun but endorse is not a noun.

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

endorsement (noun)	endorse (noun)
the act of endorsing
formal and explicit approval
a promotional statement (as found on the dust jackets of books)
a speech seconding a motion
a signature that validates something

endorsement (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