Flint vs river

Flint and river both are nouns.

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

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