river vs Yazoo

river and Yazoo both are nouns.

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

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