sexual activity vs member

sexual activity and member both are nouns.

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

sexual activity (noun)	member (noun)
activities associated with sexual intercourse	an external body part that projects from the body
	the male sex organ
	an organization that is a member of another organization (especially a state that belongs to a group of nations)
	one of the persons who compose a social group (especially individuals who have joined and participate in a group organization)
	anything that belongs to a set or class