Green’s Dictionary of Slang

1. supposed final speeches from the gallows and murderers’ confessions, usu. as peddled by street-sellers and possibly written by a hack journalist.

1859, 1860		Hotten Dict. of Modern Sl. etc.
1873		Sl. Dict. 361: Would you lend me the price of 2 Gross of Tops, Dies or Croaks, which is 7 shillings.
1887		A. Barrère Argot and Sl. 272: The criminal... would perhaps utter for the edification of the crowd his ‘tops, or croaks,’ that is, his last dying speech .
1894		Burnley Exp. 8 Aug. 4/8: The last dying speeches hawked about the streets were ‘tops’ or ‘croaks’.
1895		Crowe Aus. Sl. Dict. 21: Croaks, murderers’ confessions.

2. a dying speech.

1910

‘O. Henry’ ‘Strictly Business’ in Strictly Business (1915) 13: Jack Valentine was the only person with the ranchman when he made his (alleged) croak.

3. (also croaking) death.

1903		‘Hugh McHugh’ Out for the Coin 28: I don’t see why he should come back after the croak and haunt me.
1929		‘Ellery Queen’ Roman Hat Mystery 72: Gawd, you’re not tryin’ to tie this croakin’ around my neck, are you?
1945		R.L. Bellem ‘Poison Payoff’ Hollywood Detective Dec. 🌐 ‘How’s the private-detective business?’ [...] ‘Lousy, thanks [...] It’s getting so I don’t know where my next croaking’s coming from.’.

4. (US) a boring complainer, a whinger.

1918

H.I. Dodge Yellow Dog 58: Spot the main croaks [...] Slip ’em the yellow card [HDAS].

5. (US drugs) a mix of crack cocaine and cocaine.

1989

Hartford Courant (CT) 1 Sept. A10/1: A new generation of narcotics known as crank, croak and moon rock is invading American streets [...] corak [is] a mixture of crack and regular cocaine.