itchy vs itch

itchy is not a noun while itch is a noun.

Word	Noun	Adjective	Verb	Adverb
itchy	No	Yes	No	No
itch	Yes	No	Yes	No

itchy (noun)	itch (noun)
	an irritating cutaneous sensation that produces a desire to scratch
	a strong restless desire
	a contagious skin infection caused by the itch mite; characterized by persistent itching and skin irritation

itchy (adjective)	itch (adjective)
causing an irritating cutaneous sensation; being affect with an itch
nervous and unable to relax

itchy (verb)	itch (verb)
	have a strong desire or urge to do something
	have or perceive an itch
	scrape or rub as if to relieve itching
	cause to perceive an itch