Green’s Dictionary of Slang

back-hander n.

[SE backhander, a blow from the back of the hand]

1. a piece of negative gossip delivered ‘behind someone’s back’.

[UK]G.J. Whyte-Melville Kate Coventry (1865) 7: I know this was what John calls a ‘back-hander’ at me, but I can be so good-tempered [etc.].
[UK]G.J. Whyte-Melville Inside Bar (12th edn) 363: This was obviously a back-hander at James.
[Aus]Bulletin (Sydney) 12 Feb. 8/3: But if nor love nor ‘greed’ I get / (He thought this a ‘back-hander’), / On your good name I’ll put a ‘set,’ / With wicked lies and slander.
[UK]E. Glyn Visits of Elizabeth 299: It sounds to me like giving back-handers. The French women never talk like this.
[[Aus] Stephens & O’Brien Materials for a Dict. of Aus. Sl. [unpub. ms.] 6: BACK-HANDED TURN [...] Any injury covertly effected while professing friendship is known as a back-handed turn, such as by way of giving a man assistance or advice which leads him into danger or difficulty].

2. a drink taken out of turn or an extra drink taken while the decanter circulates.

[UK]Thackeray Newcomes II 48: Thank you, Mr. Binnie, I will take a backhander, as Clive doesn’t seem to drink.
[UK]Hotten Sl. Dict.
[UK]Sat. Rev. (London) 798: A kindly host affects not to notice a valued guest, who... helps himself to an innocent backhander [F&H].

3. (also backhand) a bribe; a payoff for services rendered.

[Aus]Truth (Sydney) 23 Dec. 4/6: I see the Assembly [...] struck off the Encampment vote as a sort of backhander to a Minstry that can’t afford a trifle to bring our countrymen home.
J. Orton Ruffian on the Stair (1967) Scene iv: Are you asking for a back-hander?
[Aus] ‘Whisper All Aussie Dict.’ in Kings Cross Whisper (Sydney) xxxii 6/1: back handler [sic]: A sling in the form of a bribe to the bobbies.
[Aus]F.J. Hardy Outcasts of Foolgarah (1975) 14: What about champagne dinners after every meeting [....] and the back hander copping over beach front developments.
[UK]J. McClure Spike Island (1981) 95: You’ve got to turn up results and, if you do, you’ll get a good backhander off the police.
[UK]J. Sullivan ‘Hole in One’ Only Fools and Horses [TV script] How many times has the landlord settled out of court with a quiet backhander to save all the aggro?
[Aus]C. Bowles G’DAY 25: A crim gives backhanders to the pollies (politicians) and knocks blokes off.
[Ire](con. 1920s) K.C. Kearns Dublin Tenement Life 70: They’d be drinking there all night and they’d get their back-hand then the next morning.
[UK]P. Baker Blood Posse 372: For a back-hander of two hundred dollars one of the workers gave me Billy’s telephone number.
[UK]Guardian G2 24 Jan. 22: Bribes, bungs and backhanders.
[UK]J. Cameron Hell on Hoe Street 105: Jesus. He was wanting a backhander. Grease my way.
[UK]K. Richards Life 349: Sometimes there’s a backhander - ‘I love you too, and here’s some smack!’.
[UK]Sun. Times Mag. 19 Dec. 62/1: The Liffey still smelt of Eurogrease and backhanders.

4. a blow delivered with the back of the hand.

[US]Eve. Star (Washington, DC) 22 Apr. 32/3: Thus honoring King Alexis [...] Slavna was giving a stinging backhander to Prince Sergius.
[UK]Galton & Simpson Hancock’s Half Hour May [radio script] I’ll give you such a backhander.
[US]P. Corris ‘Mother’s Boy’ in Heroin Annie [e-book] The guy by the window moved across and hit me with a backhander behind the ear where it doesn’t show.