Green’s Dictionary of Slang

1. (UK Und.) a house-breaker’s short crowbar.

c.1698		B.E. Dict. Canting Crew n.p.: Jenny, c. an Instrument to lift up a Grate, and whip any thing out of a Shop-window.
1725		New Canting Dict. [as cit. c.1698].
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
1788, 1796		Grose Classical Dict. of the Vulgar Tongue (2nd, 3rd edn) n.p.: Jenny. An instrument for lifting up the grate or the top of a show-glass, in order to rob it. Cant.
1808		Ordinary of Newgate Account 30 Nov. 🌐 [...] the one below answered, then hand me down the jemmy. Q. That is a slang phrase for an iron crow – A. It is one of the phrases that they have for it among many others.
1809		G. Andrewes Dict. Sl. and Cant n.p.: jenny a pick-lock.
1811		Lex. Balatronicum [as cit. 1788]. [Ibid.] Jemmy. A crow. This instrument is much used by housebreakers. Sometimes called Jemmy Rook.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue [as cit. 1788].
1827		P. Cunningham New South Wales II 228: The one being as expert a housebreaker as ever handled a jemmy.
1834		N.-Y. Daily Advertiser 20 Jan. 2/5: [A burglar had] instruments . . . for breaking open stores and houses, and among them an instrument called a London Jemmy (a short crow bar).
1843		N.Y. Daily Trib. 4 Oct. 2/5: [Thieves force] the lock of the front door with a ‘London Jemmy,’ or short crowbar found in their possession.
c.1850		G. Thompson Anna Mowbray 12: Upon the wall hung every implement used by house breakers in their lawless calling – false and skeleton keys (in flash termed dubs), dark lanterns, (glims,) small iron crow bars (London jimmies).
1859		G.A. Sala Twice Round the Clock 126: A ‘jemmy,’ a bunch of skeleton keys, a ‘knuckle duster,’ and a piece of wax candle [...] have been found in his possession.
1859		Matsell Vocabulum 46: jenney A hook on the end of a stick.
1865		Leaves from Diary of Celebrated Burglar 88/2: ‘Here,’ said Joe to me, ‘hou’d that ’ere “glim” wyle I stick this “jemmy” in t’ desk.’.
1869		Australiasian (Melbourne) 17 July 8/5: A crowbar is a jemmy and jilt. The boy who is put in at the window to open the door is called a little snake.
1876		J. Greenwood Low-Life Deeps 268: Inner pockets, in which are stowed the life-preserver, the ‘jemmy,’ the skeleton keys.
1879		Nat. Police Gaz. (NY) 13 Dec. 10/3: A ‘jimmy’ or short, well-tempered iron bar, with a claw at one end.
1880		Nat. Police Gaz. (NY) 25 Dec. 7/1: A legal friend of mine whose business [...] always has a savor of the jimmy and the centre-bit about it.
1882		Sydney Sl. Dict. (2 edn) 5: Jemmy - Small crowbar used by burglars.
1885		M. Davitt Leaves from a Prison Diary I 32: Like their aristocratic brethren of the ‘jemmy and the file,’ they will mostly all have put in various terms of previous imprisonments.
1894		Truth (Sydney) 19 Feb. 2/7: The artist [...] who points his jemmy at a bank safe or a strong room [...] is always a student.
1896		F. Hutcheson Barkeep Stories 55: ‘I was to a joint youse guys couldn’t break into wid a bushel o’ screws an’ a jimmy t’irty- foot long’.
1899		E.W. Hornung Amateur Cracksman (1992) 17: Prize it open with the jointed jemmy.
1899		Sketch (London) 22 Feb. 18: ‘I didn’t have the togs fer ter bust er house with, ’cause yer can’t carry around a lot of “relievers” (that’s jimmies an’ bars an’ false keys)’.
1901		Argus (Melbourne) 20 Sept. 6/4: If the operator in ‘jemmies’ [...] has the bad luck to be knapped, frisked, and bagged by a blue duck, a crusher, or an MP — that is to say, if he be arrested, searched, and locked up bv a policeman, he is in due course in for patter, or awaiting trial.
1906		Marvel 6 Jan. 688: A careful manipulation of the jemmy, and the window opened.
1919		‘Sax Rohmer’ Dope 30: The jemmy was thrust back into position.
1926		N. Lucas London and its Criminals 16: The jemmies, the claws and clamps, and other instruments.
1933		‘Goat’ Laven Rough Stuff 22: I [...] stuck the jemmy in the window and opened it.
1941		V. Davis Phenomena in Crime 41: Two of the ‘boys’ [...] approached the door, with the intention of breaking it in with jemmies.
1956		‘Charles Raven’ Und. Nights 17: Bunge and Harry assembled their equipment [...] his jemmy, a belladonna plaster, a wedge and nail.
1963		N. Dunn Up the Junction 95: They’re trying all the different keys, and then Bert starts smashing at it with a jemmy and it flies open.
1977		‘John le Carré’ Honourable Schoolboy 140: You might as well try and take Fort Knox with a jemmy.
1982		J. Sullivan ‘A Touch of Glass’ Only Fools and Horses [TV script] Oi, Grandad, d’you want a jemmy?
1999		G. Seal Lingo 38: Other convict terms that are either still with us or have only relatively recently dropped include: fence, flash, jemmy, kid, lark, leary (leading to lair).
2000		R.G. Barrett Leaving Bondi (2013) [ebook] He tossed the jemmy and a torch in his backpack.
2007		N. ‘Razor’ Smith Raiders 138: You can no longer just snap the padlock [...] with your trusty ‘jemmy bar.’.

2. (also jemmy stick) a walking stick.

1756

W. Toldervy Hist. of the Two Orphans IV 25: A very large pair of buckles covered his feet; and, what is now-a-days called, a little jemmy stick, employed his hands.