endorsement vs OK

endorsement and OK both are nouns.

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

As nouns, OK is a hyponym of endorsement; that is, OK is a word with a more specific, narrower meaning than endorsement:

Other hyponyms of endorsement include O.K., okay, okeh, okey, visa, nihil obstat.

endorsement (noun)	OK (noun)
the act of endorsing	an endorsement
formal and explicit approval	a state in south central United States
a promotional statement (as found on the dust jackets of books)
a speech seconding a motion
a signature that validates something

endorsement (adverb)	OK (adverb)
	an expression of agreement normally occurring at the beginning of a sentence