arousal vs sex

arousal and sex both are nouns.

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

As nouns, sex is a hypernym of arousal; that is, sex is a word with a broader meaning than arousal:

Other hypernyms of arousal include sex activity, sexual activity, sexual practice.

arousal (noun)	sex (noun)
the act of arousing	activities associated with sexual intercourse
mutual sexual fondling prior to sexual intercourse	the properties that distinguish organisms on the basis of their reproductive roles
awakening from sleep	all of the feelings resulting from the urge to gratify sexual impulses
a state of heightened physiological activity	either of the two categories (male or female) into which most organisms are divided

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