Green’s Dictionary of Slang

Paddington n.

[Tyburn, the site of London’s main 18C gallows, was in the then village of Paddington, near Marble Arch]

Pertaining to judicial execution

In compounds

Paddington fair (day) (n.) [also a pun on the actual Paddington Fair]

(UK Und.) the hanging day, the day of execution.

[UK]Mercurius Democritus 5-12 Oct. 605: He is to be soundly salted and seasoned till next Paddington Faire, that he and the rest of his Seditious Crew may give their Father Old Nick a break-fast at Hide Park corner.
[UK]Mercurius Democritus 20-27 July 74: He was conveig’d to the University of Newgate, there to learn his lesson against Paddington Fair Day where he [...] will sacrifice the precious plumb of his life.
[UK]Mercurius Democritus 28 May 10: No way of safety’s left him, then repair / To Paddington he may for help next fair.
[UK]B.E. Dict. Canting Crew n.p.: Paddington-Fair, c. an Execution of malefactors at Tyburn.
[UK]A. Smith Lives of Most Notorious Highway-men, etc. (1926) II [as cit. c.1698].
[UK]New Canting Dict. [as cit. c.1698].
[UK]Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
[UK]Grose Classical Dict. of the Vulgar Tongue n.p.: Paddington fair day an execution day, Tyburn being in the parish, or neighbourhood of Paddington.
[UK]Lex. Balatronicum.
Paddington spectacles (n.)

the hood that is pulled over the condemned man’s head before the hanging.

[UK]Partridge DSUE (1984) 847/2: early C.19.