sexual activity vs lustful

sexual activity is a noun but lustful is not a noun.

Word	Noun	Adjective	Verb	Adverb
sexual activity	Yes	No	No	No
lustful	No	Yes	No	No

sexual activity (noun)	lustful (noun)
activities associated with sexual intercourse

sexual activity (adjective)	lustful (adjective)
	vigorously passionate
	characterized by lust
	driven by lust; preoccupied with or exhibiting lustful desires