1827, "action of arousing, state of being awakened," from arouse + -al (2). Sexual association is from c. 1900.
Entries linking to arousal
arouse v.
1590s, "awaken, stir to action" (transitive), from a- (1) "on" + rouse. Related: Aroused; arousing.
-al 2
suffix forming nouns of action from verbs, mostly from Latin and French, meaning "act of ______ing" (such as survival, referral), Middle English -aille, from French feminine singular -aille, from Latin -alia, neuter plural of adjective suffix -alis, also used in English as a noun suffix. Nativized in English and used with Germanic verbs (as in bestowal, betrothal).