turn-on (n.)youdaoicibaDictYouDict[turn-on 词源字典]
that which arouses or excites, 1968, originally of psychedelic drugs, from verbal phrase turn on "activate (a mechanism)" (1833), specifically from figurative sense turn (someone) on "excite, stimulate, arouse," recorded from 1903; from turn (v.) + on (adv.).[turn-on etymology, turn-on origin, 英语词源]