river vs Ouse

river and Ouse both are nouns.

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

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