Green’s Dictionary of Slang

1. (UK Und.) to prepare.

1865		Leaves from Diary of Celebrated Burglar 7/1: Up we went to our bedrooms, where we ‘fitted-up’ our plans for the morrow.
1891		F. Harris Elder Conklin and Other Stories (1895) 3: I guess I’ll have to go and fix up.
1908		‘Doss Chiderdoss’ ‘Significant Strains’ Sporting Times 9 May 1/4: They somehow couldn’t find the right reply in half a mo’, / And, ere they could fix it up, more music sweet / Burst upon them.
1915		G. Bronson-Howard God’s Man 265: As for fitting up a joint like this.
1985		T.R. Houser Central Sl. 22: fittin Preparing [...] ‘I’m fittin’ to get some chicken’.

2. to incriminate by using false evidence, both physical and verbal.

1901		‘Rolf Boldrewood’ In Bad Company 84: He’d fix up Bill Hardwick if it came to a trial – if any man had to do a stretch over it, he’d not get off.
1902		Truth (Sydney) 28 Dec. 8/3: Last week as ever were, / A copper pulled me up to court / For nothing, I declare / [...] / I were fitted.
1924		D. Hammett ‘Death on Pine Street’ Nightmare Town (2001) 203: I’ll fix him up with a rep that will keep any jury in the world from ever believing him about anything.
1944		Sun (Sydney) 10 Nov. 2/1: ‘Once you get fitted for two it’s just as well to nod the nut to the rest’.
1953		K. Tennant Joyful Condemned 49: They’d fit him one way or the other.
1959		D. Niland Big Smoke 153: I won’t let ’em fit no mate of mine, Jacky, without a fight to protect him.
1970		G.F. Newman Sir, You Bastard 71: Every defendant claimed he was fitted.
1981		T. Wilkinson Down and Out 133: They said they were going to fit me up for something, just to get me out of the way.
1984		B. Ellem Doing Time 189: fit: to convict, with a suggestion of a manipulation of the facts. To ‘fit’ someone with a crime means to set him up with a crime which could have been committed by someone else.
1990		Tupper & Wortley Aus. Prison Sl. Gloss. 🌐 Fix-up. To frame.
1993		Smith & Noble Neddy (1998) 202: This guy got in touch with me asking could I do anything for him as he was cold [innocent] on the blue. The cops had just thrown him in for the fun of it, but he looked like getting fitted with it.
1999		Guardian G2 11 Aug. 22: Gordon Goody was adamant that the police ‘fitted me up’.
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] : fit v. 1 (also fit up or fix up) to find or fabricate evidence to secure a conviction, to frame.
2005		P. Temple Broken Shore (2007) [ebook] Forty-four years in the courts [...] I’ve seen more Abos fitted up than I’ve had hot dinners.
2008		Camden New Journal (London) 20 Mar. 2: He insisted he was an innocent bystander ‘fitted up’ by police.
2013		D. Whish-Wilson Zero at the Bone [ebook] A beating was preferable to being fitted up, to what would come later at the lockup.
2017		A. Parks Bloody January 8: ‘He fit him up?’ He shook his head. ‘Nope, whole thing was straight for once. Nairn was as guilty as they come’.
2020		A. Parks Bobby March Will Live Forever 135: ‘[T]hat’s no fair!’ [...] ‘Neither’s that boy being fitted up for something he didn’t do’.

3. to make responsible (for).

1975

‘P.B. Yuill’ Hazell and the Three-card Trick (1977) 91: Nah, we’ll fit up Desperate for that end ovvit.

4. (N.Z. prison) to take revenge on a fellow-inmate, esp. by manipulation of the prison rules.

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 69/2: fit (someone) up v. to take revenge upon a fellow inmate, specifically by taking advantage of the rules put in place by the system, rather than using violence.