USA vs MS

USA and MS both are nouns.

Word	Noun	Adjective	Verb	Adverb
USA	Yes	No	No	No
MS	Yes	No	No	No

USA (noun)	MS (noun)
the army of the United States of America; the agency that organizes and trains soldiers for land warfare	a master's degree in science
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 the Deep South on the gulf of Mexico; one of the Confederate States during the American Civil War
	a chronic progressive nervous disorder involving loss of myelin sheath around certain nerve fibers