Ouse River vs river

Ouse River and river both are nouns.

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

Ouse River (noun)	river (noun)
a river in northeastern England that flows generally southeastward to join the Trent River and form the Humber	a large natural stream of water (larger than a creek)