Green’s Dictionary of Slang

1. (Aus./US) to attack as a gang; also fig.

[1860		Melbourne Punch 2 Aug. 181/1: [I]t is while ‘double banking,’ (i. e. hooking on one or more additional teams to assist in crossing a bog, &c.,) that the Model Bullock Driver is seen to greatest advantage].
1880		Nat. Police Gaz. (NY) 3 Jan. 14/4: Never allow yourself to be double-banked in the corner of a little second story front room.
1885		Bulletin (Sydney) 11 Apr. 6/3: When Henry wasn’t doubling her up rheumatism was. It was often a tie between Henry and rheumatism as to which would grip her first, or wriggle her most. In general Henry won. Sometimes they double-banked his poor wife. Then she used to cry ‘a go,’ and stretch herself out.
1890		‘Rolf Boldrewood’ Colonial Reformer III 185: I couldn’t help rolling in, seeing the master double-banked.
1900		Bulletin (Sydney) 20 Jan. 7/2: [I]t is a grievous sin and shame that young Smith should be hauled away by a policeman and fined or imprisoned (or even hanged, if he double-banked Jones too violently) for his commendable act.
1946		Mezzrow & Wolfe Really the Blues 267: They doublebanked him and knocked him out with a piece of pipe.
1950		Goldin et al. DAUL 61/1: Double-bank, v. [...] to assault an unsuspecting victim.
1994		N. McCall Makes Me Wanna Holler (1995) 58: The best way to guarantee winning a rumble was to double-bank someone, get several guys and gang up on him.

2. (US) to trick, to doublecross; thus double banker, a swindler.

1867		Nat. Police Gaz. (NY) 26 Oct. n.p.: No ‘squaring’ ‘palming,’ ‘beaks’ and ‘cops,’ / O, nothing then so low! / No ‘double-banking’ of a ‘cove,’ / All then scratched the toe.
1894		Truth (Sydney) Feb. 1/8: ‘Well things are bad,’ said Alfred, as he strode into the sanctum, / ‘A blankey crowd of folks to pay, ’ and then he double-banked them.
1896		F. Hutcheson Barkeep Stories 14: ‘I been maced round here an’ dubbed round here an’ had de hooks t’run into me round here till I’m daffy!’.
1900		Bulletin (Sydney) 15 Dec. 10/3: Recently saw half-a-dozen rats lying in front of the Richmond Town-hall. Evidently had been purchased by the council, which thus stood a good chance of being double-banked by any passing Weary Willie.
1914		Truth (Melbourne) 7 Feb. 10/6: [headline] The Double Banker [...] Every day we see him growing / Big monopolistic fraud.
1950		Goldin et al. DAUL 61/1: Double-bank, v. To double-cross.

3. (Aus./N.Z.) to carry two people on a single horse.

1888		‘Rolf Boldrewood’ Robbery Under Arms (1922) 140: We must double-bank my horse [...] till we’re clear of the place; we didn’t want to bring a lot of horses about.
1900–10		Stephens & O’Brien Materials for a Dict. of Aus. Sl. [unpub. ms.] 63: DOUBLE-BANK: general to double load, as two men riding on one horse.
1944		Dly Mercury (Hobart, Tas.) 13 June 2/5: They were double-banking on a pony, jogging along quietly,.
1957		J. Greenway ‘Australian Cattle Lingo’ in AS XXXIII:3 165: double bank, v. phr. 1. To ride two on a horse.

4. (Aus.) to work something extra hard.

1900–10

Stephens & O’Brien Materials for a Dict. of Aus. Sl. [unpub. ms.] 63: DOUBLE-BANK: [...] to work anything over its regular capacity or strength.

5. (Aus./N.Z., also doub, dub, dubb, ride double-bank) to carry two people on one bicycle; thus double-bank, double-banker, a lift on someone else’s bicycle.

1900		Brisbane Courier 24 Aug. 4/7: As a result of ‘double-banking’ a bicycle yesterday, a boy named William Rolf, aged 7, [...] had the big toe of his right foot taken off by the chain.
1910		Narandera Argus (NSW) 25 Nov. 4/4: The exceedingly dangerous nature of the practice of double-banking a bicycle was exemplified on Wednesday by an accident, attended with serious and painful results, to a boy named Robinson, at Gillenbah.
1920		Sun. Times (Sydney) 11 Jan. 15/6: I have been dying for a bicycle of my own for quite a long time, as one of my friends has one [...] [s]he often gives me 'double-bankers' home.
1920		Sun (Sydney) 2 Aug. 2/7: [headline] ‘Double-Banking’ a Bike. Brother and Sister Hurt.
1920		Maryborough Chron. (Qld) 2 Nov. 2/5: The Deadly ‘Double’. At Rockhampton on Sunday J. Ryan was giving his wife a double bank [etc].
1932		Queensland Times (Ipswich edn) 22 Aug. 6/4: Week-end Accidents. Keith Nunn (8) was riding double bank on a push bicycle [...] when his foot became caught in the front wheel of the machine.
1937		Truth (Brisbane) 12 Sept. 10/2: Sequel to a pretty 13-year-old girl accepting the offer of a ‘double banker’ on a bicycle on September 6 was heard in .the Townsville Police Court last week.
1939		Wellington Times (NSW) 28 Aug. 2/4: Boy Cyclists Must Not ‘Double-Bank’ Any small boy who gives his pal a lift on his bicycle will be liable to prosecution under a new regulation being drafted. It will make ‘double-banking’ on bicycles a traffic offence.
1944		Newcastle Sun (NSW) 28 Aug. 2/3: Peters, in companv with two youths, left Manly on Friday night [...] At Gosford they stole another bicycle and they rode the two bicycles — one double-banking— to Wyong.
1988		McGill Dict. of Kiwi Sl. 39/1: doub/dub/dubb short for ‘doubling’, in context of giving someone a lift on your bike; Australians prefer ‘double-bank’ or ‘double-dink’.
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].

6. to have two drinks in front of one.

1935

M. Harrison Spring in Tartarus 117: ‘Have a drink!’ [...] ‘Well ... I hardly know. I seem to be double-banked already.’.