Green’s Dictionary of Slang

1. a last dying speech, usu. that delivered on the gallows, or the account of an especially gruesome trial.

1859, 1860		Hotten Dict. of Modern Sl. etc.
1861		(con. 1840s–50s) H. Mayhew London Labour and London Poor I 223/1: He murdered his wife and family, and committed suicide after – that sold as well as any ‘die’.
1873		Sl. Dict. 361: Would you lend me the price of 2 Gross of Tops, Dies or Croaks, which is 7 shillings.

2. a capital trial for which the condemned man may be executed.

1864, 1867, 1870

Hotten Sl. Dict.