Ouachita vs river

Ouachita and river both are nouns.

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

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