Yank vs USA

Yank and USA both are nouns.

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

Yank (noun)	USA (noun)
an American (especially to non-Americans)	the army of the United States of America; the agency that organizes and trains soldiers for land warfare
an American who lives in the North (especially during the American Civil War)	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