sex vs illicit

sex is a noun but illicit is not a noun.

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

sex (noun)	illicit (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)	illicit (adjective)
	contrary to accepted morality (especially sexual morality) or convention
	contrary to or forbidden by law

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