Green’s Dictionary of Slang

1. of objects or people, a thrill, sexual or otherwise.

1956		H. Ellison ‘Nedra at f:5.6’ in Pulling a Train’ (2012) [ebook] What ‘family-programmed’ television and sexploitation films have conned her into believing is a turn-on.
1967–8		Baker et al. CUSS 214: Turn on A sexually attractive person, male [...] female.
1969		‘Iceberg Slim’ Mama Black Widow 19: The musical fall of the tinkle must have been a powerful turn on.
1969		Gandalf’s Garden 6 n.d. 11: turn on: originally to take acid or smoke pot. Now also loosely applied in approval of an event, person, record, speaker, or an idea. A bad idea would be a turn-off.
1977		C. McFadden Serial 34: Ms. Murphy had suddenly decided Harvey was a ‘total turn-on.’.
1978		L. Kramer Faggots 178: It’s better than shoplifting, he thought, recalling an earlier turn-on.
1980		T. Lewis GBH 36: Who would have the bottle to take part [i.e. in a sex show] [...] This, also to the guests, was a great turn-on.
1981		J. Wambaugh Glitter Dome (1982) 58: He wasn’t very old, about the same as Tiffany Charles’ dad, which was a turn-on in itself.
1988		N. Eastwood Gardener Got Her n.p.: It’s [i.e. voyeurism] a fantastic turn-on. Don’t you think so, Greg?
1998		C. Fleming High Concept 125: [She] listed among her ‘turn-ons’ British accents, massages and credit cards.
2001		K. Sampson Outlaws (ms.) 77: The way she just quietly gets on with it [...] is one of the best turn-ons I’ve had in a long time.
2007		D. McDonald Luck in the Greater West (2008) 11: Her drunk’s confidence was beginning to be a turn-on for Whitey.
2016		‘Chelsea G. Summers’ in Hazlitt.net 8 Jan. 🌐 Cochran [...] became the first playmate to have her photos accompanied by a questionnaire divulging her ‘turn-ons’ (Corvette sports cars) and ‘turnoffs’ (fresh guys).

2. (Can.) something done by an ‘in-group’ to provoke outsiders.

1959

cited in Partridge DSUE (1984).

3. (drugs) enough of a drug to produce its desired effects.

1961		T. Taylor Baron’s Court All Change (2011) 35: Not that I could afford much myself, but Dusty always managed a turn on and I was never left out.
1963		M. Braly Shake Him Till He Rattles (1964) 121: That’s just about all that kid thinks about, and he dreams on it like it was going to be the biggest turn-on ever.
1968		L. Wolf Voices from the Love Generation 106: They’d have a big acid turn-on.
1996		P. Howard The Joy (2015) [ebook] I shouldn’t have drunk so much of it, though, not when I had a turn-on for later as well.
1997		G. Sikes 8 Ball Chicks (1998) 13: Cocaine switched from a drug for high-powered Hollywood partygoers to a turn-on for the middle classes.
1998		J. O’Connor Salesman 235: I’m on smack, I told you. I haven’t had a turn-on in days.