Green’s Dictionary of Slang

a dildo, with straps that anchor it to the user’s body.

1959		W. Burroughs Naked Lunch (1968) 25: All right, Lee!! Come out from behind that strap-on!
1970		T. Southern Blue Movie (1974) 28: I don’t think that coon had a real cock [...] I think it was a strap-on.
1998		R. Scott Rebecca’s Dict. of Queer Sl. 🌐 strap-on — a dildo worn in a harness so that it is situated in the same location as a man’s penis.
2007		W. Ellis Crooked Little Vein 10: A woman named Bob who designs strap-ons shaped like dolphin penises.
2012		(con. 1980s) I. Welsh Skagboys 92: Nora had brought a dildo around, a strap-on.
2020		S.A. Crosby Blacktop Wasteland 50: ‘The manager is this big bull dyke who probably got a strap-on pecker bigger than yours and mine put together’.