USA vs OAS

USA and OAS both are nouns.

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

USA (noun)	OAS (noun)
the army of the United States of America; the agency that organizes and trains soldiers for land warfare	an association including most countries in the western hemisphere; created in 1948 to promote military and economic and social and cultural cooperation
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