South vs USA

South and USA both are nouns.

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

South (noun)	USA (noun)
the southern states that seceded from the United States in 1861	the army of the United States of America; the agency that organizes and trains soldiers for land warfare
the region of the United States lying to the south of the Mason-Dixon line	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