Green’s Dictionary of Slang

trining n.

(UK Und.) a hanging.

c.1566		Harman Caveat for Common Cursetours in Viles & Furnivall (1907) 84: tryninge hanginge.
1592		Groundworke of Conny-catching n.p.: [as cit. c.1566].
1608		Dekker Lanthorne and Candle-Light Ch. 1: The Canters Dictionary trining, hanging.
1610		Rowlands Martin Mark-all 43: If treyning thou dost feare, thou ner will foist a Ian, / Then mill and wap and treine for me, / A gere peck in thy gan.
1637		Dekker ‘Canting Song’ in Eng. Villainies (8th edn) O2: Weele heave a Booth, and Dock agen, and Tryning scape and all is well.
1648		Dekker ‘Canters Dict.’ in Eng. Villainies (9th edn).
a.1674		‘The Rogues . . . praise of his Stroling Mort’ Head Canting Academy (1674) 20: [as cit. 1637].
1688		R. Holme Academy of Armory Ch. iii item 68c: Canting Terms used by Beggars, Vagabonds, Cheaters, Cripples and Bedlams. [...] Trining, Hanging.
c.1698		B.E. Dict. Canting Crew n.p.: Trining Hanging.
1725		New Canting Dict. [as cit. c.1698].
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.

In compounds

trining cheat (n.) (also trayning cheat, treyning cheat) [cheat n. (4)]

the gallows.

1610		Rowlands Martin Mark-all 5: Some one, that hauing ventured too farre beyond wit and good taking heede was fallen into the hands of the Magistrate, and carried to the trayning Cheates. [Ibid.] 41: Treyning cheate the gallous.
1894		Burnley Exp. 8 Aug. 4/8: The oldest name known [i.e. for hanging] is ‘treyning cheat’.