Green’s Dictionary of Slang

1. the Piccadilly Saloon.

1864, 1867, 1870

Hotten Sl. Dict.

2. (UK Und./police) Piccadilly, esp. as a favoured area for male and female prostitutes.

1909		F. Murry [perf. Marie Lloyd] Rosie had a very rosy time 🎵 On the sand she went round getting tanned / Came back again to the ’Dilly and the Strand.
1913		C. Mackenzie Sinister Street II 1100: I was out on the Dilly one night.
1928		E. Milton To Kiss the Crocodile 247: Real Chinese grub. Jes’ like the place in the Dilly at ’ome.
1938		J. Curtis They Drive by Night 260: It’s too early for her to be on the Dilly itself.
1941		V. Davis Phenomena in Crime 64: There’s a little job on the ’Dilly might suit you.
1959		C. MacInnes Absolute Beginners 46: A troop of toy soldiers, all of them with hangovers after nights of rapture down on the Dilly.
1960		G. Westwood A Minority 174: I just hang around. I talk to my mates on the Dilly and drink beer.
1975		A. Bleasdale Scully 141: W’gawin’ back t’the Dilly.
1984		(con. WW2) T. Jones Heart of Oak [ebook] ‘So there I was,’ a two -badge AB recounted from his pit, ‘on the fucking trot up the Dilly, back in ‘36.
1986–7		Maledicta IX 143: To deal first with the smaller lexicon, we turn to the dolly boys of The Dilly (Piccadilly Circus) who are on the street or on the prowl.
1991		(ref. to 1930s) in Porter & Weeks Between the Acts 139: The boys on the Dilly got to know the plain-clothes people.
2000		T. Blacker Kill Your Darlings 234: Kids who peddle their arse down the Dilly.
2004		J. McCourt ‘Vilja de Tanquay Exults’ in Queer Street 394: A tart who’ll squat and take a bit o’ rabbit / From any ponce in the ’Dilly.
2019		P. Baker Fabulosa 291/1: (the) Dilly Piccadilly Circus.
2023		R. Milward Man-Eating Typewriter 188: I emerged blinking above ground at the Dilly.

3. attrib. use of sense 2.

2004

J. McCourt ‘Vilja de Tanquay Exults’ in Queer Street 310: I must be a female impersonator / A ’Dilly drag queen on the game.