parasitical vs parasite

parasitical is not a noun while parasite is a noun.

Word	Noun	Adjective	Verb	Adverb
parasitical	No	Yes	No	No
parasite	Yes	No	No	No

parasitical (noun)	parasite (noun)
	an animal or plant that lives in or on a host (another animal or plant); it obtains nourishment from the host without benefiting or killing the host
	a follower who hangs around a host (without benefit to the host) in hope of gain or advantage

parasitical (adjective)	parasite (adjective)
relating to or caused by parasites
of plants or persons; having the nature or habits of a parasite or leech; living off another