sex vs sexual

sex is a noun but sexual is not a noun.

Word	Noun	Adjective	Verb	Adverb
sex	Yes	No	Yes	No
sexual	No	Yes	No	No

sex (noun)	sexual (noun)
activities associated with sexual intercourse
the properties that distinguish organisms on the basis of their reproductive roles
all of the feelings resulting from the urge to gratify sexual impulses
either of the two categories (male or female) into which most organisms are divided

sex (adjective)	sexual (adjective)
	having or involving sex
	of or relating to or characterized by sexuality
	involved in a sexual relationship

sex (verb)	sexual (verb)
tell the sex (of young chickens)
to evoke sexual feelings