river vs Coosa River

river and Coosa River both are nouns.

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

river (noun)	Coosa River (noun)
a large natural stream of water (larger than a creek)	river that rises in northwestern Georgia and flows southwest through eastern Alabama to join the Tallapoosa River near Montgomery and form the Alabama River