illicit vs sexual practice

illicit is not a noun while sexual practice is a noun.

Word	Noun	Adjective	Verb	Adverb
illicit	No	Yes	No	No
sexual practice	Yes	No	No	No

illicit (noun)	sexual practice (noun)
	activities associated with sexual intercourse

illicit (adjective)	sexual practice (adjective)
contrary to accepted morality (especially sexual morality) or convention
contrary to or forbidden by law