Green’s Dictionary of Slang

fan n.1

[? Fancy, the n. (1) who sported such garments, or its fan-like expanse across the frame]

(Aus./UK Und.) a waistcoat.

[UK]H. Brandon Dict. of the Flash or Cant Lang. 163/1: Fan – a waistcoat.
[UK]G.W.M. Reynolds Mysteries of London III 85/1: A Stranger—looked like a spunk fencer. [...] pair of kicksters, a fan, and a dummie .
[UK]Manchester Wkly Times 23 Aug. 11/3: The old bloak was propped (squeezed), and his skin drawn from his fan.
[US]Matsell Vocabulum.
[Aus] gloss. in Occurence Book of York River Lockup in Seal (1999) 37: I pulled down a fan and a roll of snow.
[UK]Derbyshire Courier 7 Nov. 8/1: Cant language [...] A waistcoat — fan.
[US]Trumble Sl. Dict. (1890).
[Aus]Sydney Sl. Dict. (2 edn) 4: Fan - Waistcoat.
[UK]Clarkson & Richardson Police! 321: A waistcoat ... A fan.
[Aus]Crowe Aus. Sl. Dict. [as 1882].