OK vs Arkansas

OK and Arkansas both are nouns.

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

OK (noun)	Arkansas (noun)
an endorsement	a state in south central United States; one of the Confederate states during the American Civil War
a state in south central United States	a river that rises in the Rocky Mountains in Colorado and flows southeast through Kansas and Oklahoma and through Arkansas to become a tributary of the Mississippi River

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