Ouachita vs Ouachita River

Ouachita and Ouachita River both are nouns.

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

As nouns, Ouachita and Ouachita River are synonyms defined as:

Ouachita and Ouachita River: a river that rises in western Arkansas and flows southeast into eastern Louisiana to become a tributary of the Red River

Ouachita (noun)	Ouachita River (noun)
a river that rises in western Arkansas and flows southeast into eastern Louisiana to become a tributary of the Red River	a river that rises in western Arkansas and flows southeast into eastern Louisiana to become a tributary of the Red River