ice vs ice pack

ice and ice pack both are nouns.

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

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

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

ice (noun)	ice pack (noun)
a rink with a floor of ice for ice hockey or ice skating	a waterproof bag filled with ice: applied to the body (especially the head) to cool or reduce swelling
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 large expanse of floating ice
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