Green’s Dictionary of Slang

1. to drug with chloral.

1933

‘Goat’ Laven Rough Stuff 14: We were introduced how to ‘torpedo’ a man. We used chloral, and put a small portion into a man’s drink.

2. to make drunk.

1960

(con. 1940s) D. MacCuish Do Not Go Gentle (1962) 82: That’s where Flo was sunk. Torpedoed! Thought we’d drop her off here to sleep it off.