sexual activity vs stimulate

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

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

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

sexual activity (verb)	stimulate (verb)
	cause to be alert and energetic
	act as a stimulant
	provide the needed stimulus for
	cause to do; cause to act in a specified manner
	cause to occur rapidly
	stir the feelings, emotions, or peace of
	stir feelings in