USA vs Pacific Northwest

USA and Pacific Northwest both are nouns.

Word	Noun	Adjective	Verb	Adverb
USA	Yes	No	No	No
Pacific Northwest	Yes	No	No	No

USA (noun)	Pacific Northwest (noun)
the army of the United States of America; the agency that organizes and trains soldiers for land warfare	a region of the northwestern United States usually including Washington and Oregon and sometimes southwestern British Columbia
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