ice vs icicle

ice and icicle both are nouns.

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

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

ice: water frozen in the solid state
icicle: ice resembling a pendent spear, formed by the freezing of dripping water

Other hyponyms of ice include black ice, frost, hoar, hoarfrost, rime, hailstone, ground ice, segregated ice, Taber ice.

ice (noun)	icicle (noun)
a rink with a floor of ice for ice hockey or ice skating	ice resembling a pendent spear, formed by the freezing of dripping water
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