river vs Flint

river and Flint both are nouns.

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

river (noun)	Flint (noun)
a large natural stream of water (larger than a creek)	a city in southeast central Michigan near Detroit; automobile manufacturing
	a river in western Georgia that flows generally south to join the Chattahoochee River at the Florida border where they form the Apalachicola River