improper vs sexual practice

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

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

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

improper (adjective)	sexual practice (adjective)
not suitable or right or appropriate
not appropriate for a purpose or occasion
not conforming to legality, moral law, or social convention