river vs Araguaia River

river and Araguaia River both are nouns.

Word	Noun	Adjective	Verb	Adverb
river	Yes	No	No	No
Araguaia River	Yes	No	No	No

river (noun)	Araguaia River (noun)
a large natural stream of water (larger than a creek)	a river in central Brazil that flows generally northward (with many falls) to join the Tocantins River