Green’s Dictionary of Slang

win n.

also winn, wyn
[origin unknown, but Vaux suggests, without further explanation, an abbr. of Winchester; Ribton-Turner, A History of Vagrants (1887), suggests synon. Erse pinghin, Manx ping]

1. [mid-16C–mid-19C] a penny.

2. (US) a cent (cf. penny n. (1)).