Green’s Dictionary of Slang

a farthing.

1789		G. Parker Life’s Painter 161: Farthing A fadge.
1796		Grose Classical Dict. of the Vulgar Tongue (3rd edn).
1809		G. Andrewes Dict. Sl. and Cant.
1812		Vaux Vocab. of the Flash Lang.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1834		‘I Am A Blowen Togg’d Out So Gay’ in Flare-Up Songster 16: I never goes one fadge under my price.
1835		G. Kent Modern Flash Dict.
1848		Flash Dict. in Sinks of London Laid Open.
1859, 1860		Hotten Dict. of Modern Sl. etc.
1864, 1867, 1870		Hotten Sl. Dict.
1873		Sl. Dict.
1881		Morn. Bulletin (Rockhampton, Qld) 18 July 2/6: For a farthing there are a ‘Covent Garden’ and a ‘fadge’.
1896		‘’Arry on African Affairs’ in Punch 22 Feb. 90/2: I’ll wager a crown to a fadge.
1906		E. Pugh Spoilers 5: All you got. An’ if you stick to half a fadge I’ll ... No, I won’t drown you.
1908		Bulletin (Sydney) 20 Aug. 24/1: A ‘fadge’ ’ill buy a ha’p’ny loaf – it’s them wot’s stale, I mean – / An’ the other bloomin’ farden buys yer bloomin’ margerine.
1937		Nott. Eve. Post 30 Apr. 6/3: Now we come to the humble farthing [...] it was soon turned into rhyming slang into ‘Covent Garden’. Other names are ‘quartareen’ [...] ‘fadge,’ ‘grig,’ and ‘fiddler’.