promiscuous vs sexual activity

promiscuous is not a noun while sexual activity is a noun.

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

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

promiscuous (adjective)	sexual activity (adjective)
not selective of a single class or person
casual and unrestrained in sexual behavior