Green’s Dictionary of Slang

hot stuff n.1

(US)

1. spiced rum, strong alcohol.

[US]Southern Literary Messenger Apr. 217: Cave [...] refreshing himself with about a pint of hot-stuff, rose.
[US]Daily Trib. (Bismarck, ND) 23 Oct. 4/1: Liquor is [...] ‘hot stuff.’.
[US]C.L. Cullen Tales of the Ex-Tanks 236: The switch from beer to the hot stuff made me so cautious.
[US]E. Dahlberg Bottom Dogs 137: A pimp [...] wanted to know on the sly if he wanted some hot stuff for only two bucks a shot.
[Ire]J.B. Keane Letters of Irish Parish Priest 34: The housekeeper had a notorious tooth for the hot stuff [...] As close as he watched it the whiskey began to disappear.
[Ire]J.B. Keane Bodhrán Makers 162: Only for the regular dose of the hot stuff [...] there is no way I would stay on course.
[Ire]J.B. Keane Love Bites and Other Stories 10: Of course we all knew what the hot stuff was.

2. coffee.

[US]Wash. Times (DC) 5 Oct. 5/5: Another cup or two of coffee, or ‘hot stuff’, as the prisoners call it.
[US]V.W. Saul ‘Vocab. of Bums’ in AS IV:5 341: Hot-stuff—Coffee.
[US]Mencken Amer. Lang. (4th edn) 582: Coffee is hot-stuff, mud or embalming-fluid.