Green’s Dictionary of Slang

1. (UK/US Und., also turrl) a key, esp. a skeleton or duplicate key.

1867		H.L Williams Ticket-of-Leave Man 12: I’m afraid none of my turrls (skeleton keys) are small enough.
1879		‘Autobiog. of a Thief’ in Macmillan’s Mag. (London) XL 502: It was now that I got acquainted with the use of twirls (skeleton-keys).
1891		J. Bent Criminal Life 271: Twirls ... Housebreaking implements.
1899		Newcastle Courant 18 Nov. 5/2: ‘Got the twirls,’ asked Jimmy.
1904		Dubbo Liberal (NSW) 30 Jan. 3/4: Our burglar [...] uses his ‘twirls’ or skeleton keys.
1930		(con. 1910s) D. Mackenzie Hell’s Kitchen 117: A key is a ‘twirl.’.
1935		G. Ingram Cockney Cavalcade 231: ‘Get his twirls out!’ ordered Mutt.
1935		Thieves Slang ms list from District Police Training Centre, Ryton-on-Dunsmore, Warwicks 11: Twirls: Skeleton keys.
1946		Singleton Argus (NSW) 4/2: Other fancy underworld terms for [a key] are ‘the twirl,’ and ‘the gate,’ and ‘the twist’.
1949		Monteleone Criminal Sl. (rev. edn).
1956		‘Charles Raven’ Und. Nights 86: A bunch of fifty-four twirls was far too clumsy.
1962		R. Cook Crust on its Uppers 26: Let’s get the twirl out and swing back the old baronial doors.
1979		F. Norman Too Many Crooks Spoil the Caper 120: Pete’s got the twirl.
1989		(con. 1950s–60s) in G. Tremlett Little Legs 87: I had entered a flat [...] using a twirl to get in.
2004		(con. 1980) N. ‘Razor’ Smith A Few Kind Words and a Loaded Gun 243: Sometimes the boys would use ‘twirls’, a set of double-edged FS keys, to get into cars.

2. (UK prison, also twirler) a prison officer.

1891		J. Bent Criminal Life 272: There is a twirl here from another stir.
1930		(con. 1910s) D. Mackenzie Hell’s Kitchen 117: A key is a ‘twirl.’ Prison officers, too, are known as ‘twirls,’ because of the keys which they carry.
1935		Thieves Slang ms list from District Police Training Centre, Ryton-on-Dunsmore, Warwicks 11: Twirlers: Prison officers.
1939		V. Davis Gentlemen of the Broad Arrows 148: Two of the worst ‘twirls’ ever seen in a prison-house.
1943		J. Phelan Letters from the Big House 37: The twirl was laying it on, hissing like, and spitting through his teeth.
1958		F. Norman Bang To Rights 9: As I came along the passage [...] a twirl shouted, ‘One lagging; C.T.’.
1981		(con. 1900–30) A. Harding in Samuel East End Und. 284: Twirl – Warder.