Green’s Dictionary of Slang

die n.1

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

[UK]Hotten Dict. of Modern Sl. etc.
[UK](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’.
[UK]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.

[UK]Hotten Sl. Dict.