Green’s Dictionary of Slang

drop dead! excl.

(orig. US) a general excl. of dismissal.

[US]W.R. Burnett Little Caesar (1932) 194: ‘Drop dead,’ said Liska.
[US]J.H. O’Hara Appointment in Samarra (1935) 181: ‘Oh drop dead,’ said Whit.
[UK]C. Day Lewis Otterbury Incident 114: ‘Kindly do me the favour of dropping down dead,’ Toppy replied.
[US]J.H. Burns Lucifer with a Book 61: Ah, drop dead, willya?
[US]B. Schulberg On the Waterfront (1964) 116: Do me a favour ’n drop dead.
[US]R. Prather Scrambled Yeggs 85: That’s exactly what I wish you’d do, Scott. Drop dead.
[Aus]‘Nino Culotta’ Cop This Lot 10: Joe said he wished the inspector would go away and drop dead.
[US]K. Brasselle Cannibals 89: ‘Say something J.J.B.’ ‘Drop dead!’.
[US](con. 1950s) H. Junker ‘The Fifties’ in Eisen Age of Rock 2 (1970) 100: Wise up. Don’t bug me. Drop dead. DDT.
[US]L. Rosten Dear ‘Herm’ 4: So kindly give whoever is calling me this message: ‘Drop dead!’.
[US]A. Hoffman Property Of (1978) 6: ‘Just shut up.’ ‘Drop dead,’ I said.
[US] Village Voice (N.Y.) 13 May n.p.: New York to the Arts: Drop Dead [R].
[US]E. Richards Cocaine True 143: Fuck it. Drop dead! I’ve got my gun.
[Aus]Penguin Bk of More Aus. Jokes 356: Drop dead, you pommy bastard.
[US]C. Hiaasen Lucky You 322: ‘It’s been nice chatting with you, Bernie.’ ‘Drop dead.’.

In compounds

drop-dead money (n.)

money, the possession of which enables one to tell the world to drop dead! i.e. bestows freedom on its possessor.

J. Arthur ‘Layoffs, The Best Thing’ on ‘Heads Up!’ Archive 28 Feb. 🌐 [I] started a vigorous investment program so that I’d have ‘drop dead’ money: if I didn’t like how the company was treating me or clients I could just say ‘drop dead’ because I’d have more than enough money to live on.