Green’s Dictionary of Slang

1. a fortune of £100,000, usu. as a legacy or as the possession of an heiress; thus half a plum n., £50,000.

1689–1702		Earl of Ailesbury Memoirs (1890) 634: Whigs are the more rich, especially in King William’s time [...] when the tally trade alone brought in to some a hundred thousand pounds, which they then called a plum .
1703		M. Prior Ladle in Works (1959) I 207: The Miser must make up his Plumb, And dares not touch the hoarded Sum.
1710		R. Steele Tatler No. 244 n.p.: An honest Gentleman who sate next to me, and was worth Half a Plumb, stared at him.
1725		View of London & Westminster (2nd part) 24: Nick Niggard is [...] universally known to be what the World calls a Plumb Man.
1751		Cleland Memoirs of a Coxcomb 2: A sum that did not want many thousand pounds of making what is called, in the language of Change-Alley, a plumb.
1751		Smollett Peregrine Pickle (1964) 1: He was the son of a merchant in London, who [...] acquired a plentiful fortune, tho’, to his infinite regret, he died before it amounted to a Plum.
1766		Colman & Garrick Clandestine Marriage III ii: My brother Heidelberg was a warm man, a very warm man; and died worth a plumb at least.
1779		Nocturnal Revels I 251: Mend—z was at this period a merchant of opulence [...] worth near a plumb.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: Plumb, an hundred thousand pounds.
1792		T. Hurlstone Just in Time in Sporting Mag. Dec. I 160/2: Lord Oddly [...] marrying my dutiful little Augusta, with almost a plumb, to a foolish medical puppy.
1797		T. Morton A Cure for the Heart Ache in Inchbold (1808) XXV 30: A plum! Oh, sweet, agreeable, little, short word!
1800		W. Wilding Man of Pleasure 3: A sum that did not want many thousands of pounds of making what is called, in the language of Change-Alley, a plum.
1811		Lex. Balatronicum [as cit. 1785].
1823		[C.M. Westmacott] Mammon in London 1 326: Choose the discreet widow, whom the dotard C— left nine plums, at the expense of his family.
1826		Vulgarities of Speech Corrected n.p.: £100,000 — £50,000 A plumb — half a plumb.
1832		Brighton Guardian 3 Oct. 4/1: Much more than others I deserve / [...] / Five plums I’ve got, while others starve.
1838		Crim.-Con. Gaz. 1 Sept. 24/1: This gentleman [...] was reported to be worth a plumb.
1843		Bellew Memoirs of a Griffin I 177: ‘Egad, I think we’ll see you go home with your plum, Augustus, yet’.
1844		Thackeray Barry Lyndon (1905) 169: An English tallow-chandler’s heiress, with a plum to her fortune.
1856		C. Reade It Is Never Too Late to Mend II 317: I believe there are plumbs of gold not thirty miles from here in such spots waiting only to be dug out.
1857		N&Q Ser. 2 4 July n.p.: [...] much as a bull (or a hog) stand arbitrarily for a five-shilling-piece, [...] with equal propriety might a plum stand for £100,000 [F&H].
1866		Letters by an Odd Boy 135: The plum he pulled out may have been the financial plum, £100,000; if so, of course I take my cap off, and shout ‘Vive le Horner!’.
1873		Sl. Dict.
1890		‘Rolf Boldrewood’ Squatter’s Dream 104: Twenty years on the Warroo with the certainty of a plum and a baronetcy in the end, would kill me as surely as sunstroke.
1898		W. Besant Orange Girl I 79: ‘What?’ he cried. ‘You the only son of Sir Peter Halliday [...] the greatest merchant in the City: the heir to a plum—what do I say? Three or four plums at least.’.
1919		Smith’s Wkly (Sydney) 7 June 9/6: Slang of Money [...] A million is a ‘marigold’; £100,000 is a ‘plum.’ £1000 is a ‘cow’.

2. a rich man or woman.

1709		J. Addison Tatler 100 3: Several who were Plumbs, or very near it, became Men of moderate Fortunes.
1741		Secret Hist. of Betty Ireland (9 edn) 8: She resolved to [...] try what fortune she might meet with in England, hoping she might pass their for a Plumb, whose Blue was not worn off.
1832		Egan Bk of Sports 195: We have given our opinion on claret with some of the ‘Plumbs’.

3. a fortune or a substantial reward; that which will yield one.

1847		‘Epistle from Joe Muggins’s Dog’ in Era (London) 17 Oct. 3/2: Some people’s Christmas puddins [...] are likely to go precious short of ‘plums’.
1870		Sportsman (London) 7 Apr. 2/1: When the Government took up the [telegraph] wires, some big ‘plums’ were distributed among the shareholders of the companies whose lines were transferred to the country, let us hope for the country’s good.
1885		Bulletin (Sydney) 11 Apr. 18/4: I’m looking about for a good investment or two – a nice little bit of land on one of the new lines of railway at about 5s. a foot, warranted to turn in £5 in a twelvemonth. I heard of such a thing the other day, but the auctioneer was too much for me; he ‘worked the oracle’ and stuck to the ‘plum’ himself.
1894		Mirror of Life 14 Apr. 2/3: [of winning a horserace] Convent was placed third, and Kilsallaghan carried off the ‘plum’.
1900		St Andrews Citizen 20 Jan. 1/6: [advert] A Chance Worth Snatching / A Big Plum to All Economists.
1903		Bulletin (Sydney) 2 July 14/3: As a youth, he had done some mining thereabouts, and was quick to recognise Mount Morgan as a possible plum.
1952		Lait & Mortimer USA Confidential 69: Some of whose kings split a billion-dollar gambling plum.

4. a political office that is lucrative, esp. when it has been obtained by bribery or influence of some kind; in the sea novels of P. O’Brian (set c. 1810) plum is used to designate a desirable command.

1887		Courier-Journal (Louisville, KY) 13 Jan. 3/4: Senator Beck gets the credit for most of the Federal appointments in Mason county [...]. The boys enjoying the plums will support anybody who is for him and them [DA].
1897		Wichita Dly Eagle (ND) 26 Aug. 4/2: He is after the ‘office-holding, plum-grabbing class’ within the Democratic party.
1911		N.Y. Eve. Post 3 Jan. 8: The ‘plum’ is a luscious fruit in the shape of an office under the State government, which many people are on the lookout to secure [DA].
1921		Rock Is. Argus (IL) 2 Dec. 9/2: She has just been elected as register of the county of New York — the richest political plum that has ever fallen into the lap of a woman.
1939		W. Winchell On Broadway 20 June [synd. col.] If Grover Whalen doesn’t succeed in getting a major political plum [...].
1945		Somerset News 22 Mar. 1/1: At least one young lawyer who need not look to either Democratic faction or to the Republicans for political plums in order to keep himself alive [DA].
1949		Chicago Trib. 30 Nov. 21/1: [heading] Democrats Get $17.68 Per Day Census Plums [DA].
1956		‘Ed Lacy’ Men from the Boys 🌐 For the higher-ups, there are some good-paying jobs, the usual political plums.
1981		McKee & Chisenhall Beale Black & Blue 27: The Beale Street beat was a plum for policemen on the take.

5. a fool.

2000		J.J. Connolly Layer Cake 110: They both have a natural talent to inspire irritation in plums and logs world-wide.
2009		R. Milward Ten Storey Love Song 119: Bobby feels like an utter plum tramping into Burger King with the rest of the National Express goons.