guarantee vs endorse

guarantee is a noun but endorse is not a noun.

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

As verbs, endorse is a hypernym of guarantee; that is, endorse is a word with a broader meaning than guarantee:

guarantee: stand behind and guarantee the quality, accuracy, or condition of
endorse: be behind; approve of

Other hypernyms of guarantee include back, indorse, plump for, plunk for, support.

As verbs, endorse is a hyponym of guarantee; that is, endorse is a word with a more specific, narrower meaning than guarantee:

guarantee: stand behind and guarantee the quality, accuracy, or condition of
endorse: guarantee as meeting a certain standard

Other hyponyms of guarantee include cover, insure, underwrite, certify, indorse.

guarantee (noun)	endorse (noun)
a written assurance that some product or service will be provided or will meet certain specifications
an unconditional commitment that something will happen or that something is true
a collateral agreement to answer for the debt of another in case that person defaults

guarantee (verb)	endorse (verb)
give surety or assume responsibility	sign as evidence of legal transfer
promise to do or accomplish	be behind; approve of
stand behind and guarantee the quality, accuracy, or condition of	guarantee as meeting a certain standard
make certain of	give support or one's approval to