U.S. vs Rio Bravo

U.S. and Rio Bravo both are nouns.

Word	Noun	Adjective	Verb	Adverb
U.S.	Yes	No	No	No
Rio Bravo	Yes	No	No	No

U.S. (noun)	Rio Bravo (noun)
the executive and legislative and judicial branches of the federal government of the United States	a North American river; boundary between the United States and Mexico; flows into Gulf of Mexico
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