Green’s Dictionary of Slang

plum n.2

also plumb
[SE plumb, a lump of lead; note Egan, Book of Sports (1832): ‘City Slang. — A man worth 100,000’]

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

[UK]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 .
[UK]M. Prior Ladle in Works (1959) I 207: The Miser must make up his Plumb, And dares not touch the hoarded Sum.
[UK]R. Steele Tatler No. 244 n.p.: An honest Gentleman who sate next to me, and was worth Half a Plumb, stared at him.
[UK]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.
[UK]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.
[UK]Colman & Garrick Clandestine Marriage III ii: My brother Heidelberg was a warm man, a very warm man; and died worth a plumb at least.
[UK]Nocturnal Revels I 251: Mend—z was at this period a merchant of opulence [...] worth near a plumb.
[UK]Grose Classical Dict. of the Vulgar Tongue n.p.: Plumb, an hundred thousand pounds.
[UK]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.
[UK]T. Morton A Cure for the Heart Ache in Inchbold (1808) XXV 30: A plum! Oh, sweet, agreeable, little, short word!
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.
[UK]Lex. Balatronicum [as cit. 1785].
[UK][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.
[UK]Vulgarities of Speech Corrected n.p.: £100,000 — £50,000 A plumb — half a plumb.
[UK]Brighton Guardian 3 Oct. 4/1: Much more than others I deserve / [...] / Five plums I’ve got, while others starve.
[UK]Crim.-Con. Gaz. 1 Sept. 24/1: This gentleman [...] was reported to be worth a plumb.
[Ind]Bellew Memoirs of a Griffin I 177: ‘Egad, I think we’ll see you go home with your plum, Augustus, yet’.
[UK]Thackeray Barry Lyndon (1905) 169: An English tallow-chandler’s heiress, with a plum to her fortune.
[UK]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.
[UK]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].
[US]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!’.
[UK]Sl. Dict.
‘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.
[UK]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.’.
[Aus]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.

[UK]J. Addison Tatler 100 3: Several who were Plumbs, or very near it, became Men of moderate Fortunes.
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.
[UK]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.

[UK]‘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’.
[UK]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.
[Aus]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.
[UK]Mirror of Life 14 Apr. 2/3: [of winning a horserace] Convent was placed third, and Kilsallaghan carried off the ‘plum’.
[UK]St Andrews Citizen 20 Jan. 1/6: [advert] A Chance Worth Snatching / A Big Plum to All Economists.
[Aus]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.
[US]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.

[US]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].
[US]Wichita Dly Eagle (ND) 26 Aug. 4/2: He is after the ‘office-holding, plum-grabbing class’ within the Democratic party.
[US]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].
[US]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.
[US]W. Winchell On Broadway 20 June [synd. col.] If Grover Whalen doesn’t succeed in getting a major political plum [...].
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].
[US]Chicago Trib. 30 Nov. 21/1: [heading] Democrats Get $17.68 Per Day Census Plums [DA].
[US]‘Ed Lacy’ Men from the Boys 🌐 For the higher-ups, there are some good-paying jobs, the usual political plums.

5. a fool.

[UK]J.J. Connolly Layer Cake 110: They both have a natural talent to inspire irritation in plums and logs world-wide.

In phrases

worth a plum (adj.) (also worth one’s plum) [NB N&Q 2 Ser. 1 Aug. 1857: ‘Worth a plum’ —In tracing the expression, ‘he has got a plum,’ to the Spanish phrase, ‘tiene pluma’ (he has got plumage, or, he has got a plume, spoken of a man who had ‘feathered his nest,’ or acquired wealth)]

wealthy; yielding a high income.

[UK]Morn. Post (London) 16 Oct. 3/4: His labour through life was — ‘to die worth a plum’.
Kentish Wkly Post 23 Feb. 4/4: His creditors [...] / For sure said that he’ll neve fail, / Who’s always worth a plum.
[Ire]Dublin Eve. Packet 7 Mar. 3/3: Lord Concurry secured [...] for his brother-in-law [...] a living worth a plum.
[UK]Leicester Chron. 2 Mar. 1/6: You may go to bed worth a plum and rise not worth a groat.
[UK]F.E. Smedley Lewis Arundel 310: Old Girkin died worth a plum.
[UK]‘Ducange Anglicus’ Vulgar Tongue 25: plum n. Worth a plum. A rich man.
[UK](con. 1840s–50s) H. Mayhew London Labour and London Poor II 451/2: In the same self-complacent tone that we may imagine might be used by a grocer, worth his ‘plum’.
[UK]Cheltenham Chron. 1 July 2/4: .
[UK]Hartlepool Northern Dly Mail 23 Sept. n.p.: I was introduced to [...] a wealthy spur-maker, who was reputed to be worth a plum.
[UK](ref. to mid-19C) Bucks Herald 30 July 13/3: 75 Years Ago [...] to be ‘wirth a plum’ is as much as to say that a person has a tidy balanace at his bankers.