downfall vs sleet

downfall and sleet both are nouns.

Word	Noun	Adjective	Verb	Adverb
downfall	Yes	No	No	No
sleet	Yes	No	Yes	No

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

downfall: the falling to earth of any form of water (rain or snow or hail or sleet or mist)
sleet: partially melted snow (or a mixture of rain and snow)

Other hyponyms of downfall include fine spray, hail, rain, rainfall, snow, snowfall, virga.

downfall (noun)	sleet (noun)
a sudden decline in strength or number or importance	partially melted snow (or a mixture of rain and snow)
failure that results in a loss of position or reputation
the falling to earth of any form of water (rain or snow or hail or sleet or mist)

downfall (verb)	sleet (verb)
	precipitate as a mixture of rain and snow