falls vs cataract

falls and cataract both are nouns.

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

As nouns, cataract is a hyponym of falls; that is, cataract is a word with a more specific, narrower meaning than falls:

Other hyponyms of falls include cascade.

falls (noun)	cataract (noun)
a steep descent of the water of a river	a large waterfall; violent rush of water over a precipice
the petals or sepals of a flower that bend downward (especially the outer perianth of an iris)	an eye disease that involves the clouding or opacification of the natural lens of the eye