Green’s Dictionary of Slang

1. to cheat out of, to defraud; to inflate the value.

1823		[C.M. Westmacott] Mammon in London 1 300: A novel comes out [...] the various partners of the concern duff it into notice by fraudulent criticisms [...] and the gulled public pays.
1826		Pierce Egan’s Life in London 9 Apr. 502/3: DUFFING AN EDlTOR.—Mr.Josias Bond [was] charged with having obtained the sum of 4l. and false and fraudulent pretences—to wit, by persuading the complainant that sixpenny calico was good fine Holland of 5s. a yard.
1827		J. Wight More Mornings in Bow St. 77: M’Gragh [...] was placed at the bar on a charge of double duffing a Mr Gow.
1935		Thieves Slang ms list from District Police Training Centre, Ryton-on-Dunsmore, Warwicks 4: Duffing the pawnbroker: Pledging an article for more than its value and selling [the] ticket.

2. to make old goods look like new.

c.1838

J. Vaill in Memoirs (1839) 26: My pillow was a duffed great coat, and our covering narrow Indian blankets .

3. (also doff) to make poor quality new goods look old, and thus of better quality; thus duffing n., duffer n. a person who does such a thing.

1841		‘Nothing Like Pride About Me’ Dublin Comic Songster 256: I vonce doffed my holiday togs [...] And had a coat fronted vith frogs.
1861		(con. 1840s–50s) H. Mayhew London Labour and London Poor II 19/2: When purchased by the music-duffers, they are discoloured so as to be made to look old. [Ibid.] 201/1: Nor is it to violins that this duffing or sham second-hand trade is confined.

4. to sell ordinary goods that are touted as smuggled contraband.

1861		(con. 1840s–50s) H. Mayhew London Labour and London Poor II 68/1: When he hawks birds he always dresses like a countryman, and duffs that way. [Ibid.] 70/2: He will often duff cigars and other things in preference, or perhaps vend really smuggled and good cigars or tobacco.
1869		J.C. Parkinson Places and People 20: I know them Chinamen well [...] they’ll beg, and duff, and dodge about the West-end.
1873		Sl. Dict.
1887		W.E. Henley ‘Villon’s Straight Tip’ in Farmer Musa Pedestris (1896) 176: Suppose you screeve, or go cheap-jack? [...] Suppose you duff? or nose and lag? / Or get the straight, and land your pot?
1900–10		Stephens & O’Brien Materials for a Dict. of Aus. Sl. [unpub. ms.].

5. (Aus.) to steal (cattle or horses); thus duffing n.

1865		Sydney Morn. Herald 26 Oct. 2/4: [I]t was ascertained that a ‘mickey’ signified an unbranded animal, and ‘duffing’ was the slang title for cattle stealing.
1886		Melbourne Punch 15 July n.p.: Cattle duffers on a jury may be honest men enough, / But they’re bound to visit lightly sins in those who cattle duff.
1888		‘Rolf Boldrewood’ Robbery Under Arms (1922) 5: Poaching must be something like cattle and horse duffing.
1890		‘Rolf Boldrewood’ Colonial Reformer III 54: What does Miss Neuchamp know about duffing and sticking up?
1903		J. Furphy Such is Life 12: You and I are seized of the true inwardness of duffing; but to those who live cleanly, as noblemen should, this would appear a dirty transaction.
1910		Bulletin (Sydney) 25 Aug. 40/4: Bill, [...] you did honest work duffin’ cattle from old Robertson’s run – enough to earn you seven years if you had your due.
1923		J. Bowes Jackaroos 74: There’s a good deal of duffing going on. [...] Old Tom Brown of Yucadoo reckons he lost all out of five hundred last year.
1936		(con. 1830s–60s) ‘Miles Franklin’ All That Swagger 118: Wong brought them. He thought someone had duffed them.
1953		Courier Mail (Brisbane) 18 Aug. 2/9: A cattle stealer was a duffer and stolen cattle were duffed.
1957		J. Greenway ‘Australian Cattle Lingo’ in AS XXXIII:3 165: duff, v. To steal cattle. The equivalent of American rustle.
1986		R. Beckett Dinkum Aussie Dict. 23: Duff: If one duffs cattle one steals them.

6. (Aus.) to alter the brands on (stolen) cattle; thus duffing n. and adj.

1869		E.C. Booth Another England 138: The man who owned the ‘duffing paddock’ was said to have a knack of altering cattle brands.
1877		Queenslander (Brisbane) 10 Mar. 21/1: His horses are re-branded and his calves are ‘duffed’.
1880		Bulletin (Sydney) 6 Nov. 4/4: And he ‘duffed’ the squatter’s cattle. / And he ‘pounded’ all his sheep.
1890		‘Rolf Boldrewood’ Squatter’s Dream 162: I knew Redcap when he’d think more of duffing a red heifer than all the money in the country.
1900		Bulletin (Sydney) 3 Mar. 14/3: Weary Humper: ‘Any great events been comin’ off up in the town lately, Billy?’ / Billy: ‘My word, yes – lots. Me brother Tom just got six months fer cow-duffin’; ole Murphy’s been wipen’ the street with the new trap.’.
1926		K.S. Prichard Working Bullocks 61: Well, there was a good deal of duffing goin’ on about then.
1999		G. Seal Lingo 47: The popularity of this form of robbery can be judged from various terms used to describe it — poddy-dodging, duffing, gully-raking.

7. (UK und.) to concoct and/or pass off a worthless article as something valuable or exotic.

1870		Sportsman (London) 5 Feb. 4/1: A mermaid [...] was ‘duffed up’ [by P.T. Barnum] by joining a monkey's body on to the fag end of a fish.
1880		New Babylon (London) 24 July 4/2: ‘Give me the bracelet and don’t have so much jaw about it. But if I can stand your duffing Cape diamonds, I can't stand your duffing champagne’.

8. to blunder, to make a mess of.

1908		A.N. Lyons Arthur’s 148: You’re fairly duffin’ it between you.
1909		J. Ware Passing Eng. of the Victorian Era 119/2: Duffing (Soc. and Peoples’, 1880 on). The outcoming adjective of ‘duffer’ and ‘duff’. By 1897 this word became one of the most active qualitatives in the language. As a verb it had by this time come to be thoroughly conjugated ; e.g., ‘He duffs everything he touches.’ ‘He is the most duffing duffer that ever duffed.’ ‘He has duffed, he does duff; and he will duff for ever.’.
1975		G. Underwood ‘Razorback Sl.’ in AS L:1/2 58: duff vt Ruin; do poorly on. ‘I duffed that physics test.’.
1985		B. Robinson Aussie Bull 28: [A] ‘duffed’ seven iron [...] where the ball tears along the ground, runs through the bunker and stops four centimetres [...] from the hole.
2000		Penguin Bk of All-New Aus. Jokes 186: After she repeated duffed shots, the pro said: ‘You have a death-grip on the club and it’s killing your power.’.

9. (Aus.) in weakened use, to use (a possession, a place) without the owner’s permission; spec. to pasture cattle on someone else’s land.

1905		‘The Eumerella Shore’ in ‘Banjo’ Paterson Old Bush Songs 47: For it’s easier duffing cattle on the little piece of land / free selected on the Eumerella shore.
1914		Bulletin (Sydney) 3 Dec. 13/2: I was camped on the reserve near his place, with a few million weaners, one cold, wet night last winter, when he emerged through the rain and securely lashed up his sliprails with wire, to prevent me from ‘duffing’ my horse into his barren paddock.

10. to smuggle.

1941

K. Tennant Battlers 288: There was no feed for the horses in the lane, so in low undertones it was decided to duff them in on the banks of the canal, and get them out before dawn, when the inspector would be riding around.

11. see duff up v.