falls vs river

falls and river both are nouns.

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

falls (noun)	river (noun)
a steep descent of the water of a river	a large natural stream of water (larger than a creek)
the petals or sepals of a flower that bend downward (especially the outer perianth of an iris)