sex activity vs stimulate

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

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

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

sex 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