U.S. vs OK

U.S. and OK both are nouns.

Word	Noun	Adjective	Verb	Adverb
U.S.	Yes	No	No	No
OK	Yes	No	No	Yes

U.S. (noun)	OK (noun)
the executive and legislative and judicial branches of the federal government of the United States	an endorsement
North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776	a state in south central United States

U.S. (adverb)	OK (adverb)
	an expression of agreement normally occurring at the beginning of a sentence