Green’s Dictionary of Slang

1. (US Und.) a thief, a cheat.

1931		‘Und. “Lingo” Brought Up-to-Date’ L.A. Times 8 Nov. K3: BENDER: A thief; cheater.
1933		‘Paul Cain’ Fast One (1936) 100: A couple of benders came in [...] They’d been waiting [...] to find out what they had to heist.
1949		Monteleone Criminal Sl. (rev. edn) 20: bender A thief; a cheater; a petty thief.

2. a stolen car.

1938		J.E. Hoover Persons in Hiding 247: This car’s a bender. One of your gang probably stole it.
1948		J. Evans Halo for Satan (1949) 123: It may be a bender.
1948		Mencken Amer. Lang. Supplement II 724: Bender, tomato or puppy. A stolen car.
1949		Monteleone Criminal Sl. (rev. edn) 20: bender [...] a stolen automobile.
2017		M. Taylor in Spitalfields Life 1 Oct. 🌐 In those days, you had a lot of villains and benders came here, smart people. They all showed respect for each other.

3. a robbery.

2000

N. Barlay Crumple Zone 182: Are we robbin’ gaffs up Chorleywood? Or just visting your auntie? — Jus’ visitin’ as it goes. You fink Ah’m gonna take you wiv me on a bender.