USA vs North America

USA and North America both are nouns.

Word	Noun	Adjective	Verb	Adverb
USA	Yes	No	No	No
North America	Yes	No	No	No

USA (noun)	North America (noun)
the army of the United States of America; the agency that organizes and trains soldiers for land warfare	the nations of the North American continent collectively
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 continent (the third largest) in the western hemisphere connected to South America by the Isthmus of Panama