ice vs icefall

ice and icefall both are nouns.

Word	Noun	Adjective	Verb	Adverb
ice	Yes	No	Yes	No
icefall	Yes	No	No	No

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

Other hyponyms of ice include drift ice, neve, ice pack, pack ice, ice shelf, shelf ice.

ice (noun)	icefall (noun)
a rink with a floor of ice for ice hockey or ice skating	a steep part of a glacier resembling a frozen waterfall
an amphetamine derivative (trade name Methedrine) used in the form of a crystalline hydrochloride; used as a stimulant to the nervous system and as an appetite suppressant
a frozen dessert with fruit flavoring (especially one containing no milk)
a flavored sugar topping used to coat and decorate cakes
the frozen part of a body of water
diamonds
water frozen in the solid state