arctic vs icy

arctic is a noun but icy is not a noun.

Word	Noun	Adjective	Verb	Adverb
arctic	Yes	Yes	No	No
icy	No	Yes	No	No

As adjectives, arctic and icy are synonyms defined as:

Other synonyms of arctic include frigid, gelid, glacial, polar.

arctic (noun)	icy (noun)
a waterproof overshoe that protects shoes from water or snow

arctic (adjective)	icy (adjective)
extremely cold	extremely cold
	devoid of warmth and cordiality; expressive of unfriendliness or disdain
	covered with or containing or consisting of ice
	shiny and slick as with a thin coating of ice