river vs Ouachita

river and Ouachita both are nouns.

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

river (noun)	Ouachita (noun)
a large natural stream of water (larger than a creek)	a river that rises in western Arkansas and flows southeast into eastern Louisiana to become a tributary of the Red River