Yazoo River vs river

Yazoo River and river both are nouns.

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

Yazoo River (noun)	river (noun)
a river that rises in west central Mississippi and flows southwest to empty into the Mississippi River above Vicksburg	a large natural stream of water (larger than a creek)