Green’s Dictionary of Slang

a half-a-crown (12.5p).

c.1698		B.E. Dict. Canting Crew.
1725		New Canting Dict.
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict.
c.1750–1882		B.M. Carew Life and Adventures.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1890–1904		Farmer & Henley Sl. and Its Analogues.