Green’s Dictionary of Slang

1. any nameless object, or person, or situation.

1720		C. Shadwell Irish Hospitality I i: I am acquainted with all the topping Procurers in all the great Streets, from Mother Whatd’yecallum’s in Drury-Lane, to Mother Thing’em’s in Leicester-Fields.
1766		Derby Mercury 23 May 1/1: They [...] never failed at Mrs Thing-a-my’s in Soho-Square.
1774		J. O’Keeffe Tony Lumpkin in Town (1780) 15: [I] saw Lord Thingumme’s fine coach.
1784		Rambler’s Mag. Mar. 88/1: What a devilish fine dingy picture has he given us of that Lord Thingamy.
1788		G.A. Stevens Adventures of a Speculist I 86: There’s Bet, that my Lord Thing-o’-me keeps.
1795		Sporting Mag. Mar. V 297/2: They all belonged, I understood, to the city concert, and the assembly; never failed at Mrs. Thing-a-my’s in Soho Square [etc.].
1800		Sporting Mag. June XVI 126/2: A rout at Mrs. Such-a-one’s, Mrs. What-d’ye-call-her’s Gala – and Madam Thing-a-my’s Ball.
1818		‘Thomas Brown’ Fudge Family in Paris Letter I 7: A good orthodox work is much wanting just now, / To expound to the world the new — thingummie — science.
1821		W.T. Moncrieff Tom and Jerry I iv: Very well, Mr. Thing-emy.
1823		[C.M. Westmacott] Mammon in London 1 271: ‘A bit of cabbage, of you please, Mr Thingumme’.
1827		J. Wight More Mornings in Bow St. 18: ‘Mr Thingummy [...] you are one of the troublesomest persons going’.
1837		‘Oliver Twist’ in Bentley’s Misc. Feb. 107: ‘It’s all over, Mrs. Thingummy,’ said the surgeon, at last.
1838		‘Alfred Crowquill’ Seymour’s Humourous Sketches (1866) 1: The guns hasn’t got them thingummy ‘caps,’ but that's no matter, for cousin says them cocks won’t always fight.
1840		R.B. Peake Devil In London III iv: Come, Miss Fussock, where’s our thingamy?
1841		Lloyd’s Companion 19 Sept. 1/4: ‘And what do you mean to do with the young ’uns, eh, Mrs Thingamy?’.
1842		Wkly Rake (NY) 9 July n.p.: Can you not picture in your mind’s eye, the thing-a-mee’s which may rest against it [i.e. a corset] .
1855		J. Brougham Basket of Chips 327: Let Mounseer Thingamy, or a Si’nory Whatyoucallem, wag is beard at ’em.
1861		M.E. Braddon Trail of the Serpent 359: Old mother Thingamy down Blind Peter.
1865		Dickens Our Mutual Friend (1994) 250: The spontaneous thingummies of the incorruptible whatdoyoucallums.
1867		Sportsman 9 Nov. 2/1: Notes on News [...] ‘It was Thingummy’s business, you know’.
1870		Hotten Sl. Dict. 255: THINGUMY [...] the name of a thing which cannot be recollected at the instant.
1875		‘Aliph Cheem’ Lays of Ind (1905) 80: Sir Thingamy So-and-so.
1880		Bulletin (Sydney) 10 Apr. 3/3: But bless ye we ain’t found dead / As the Bulletin’s ‘thingamy’ said.
1886		Stephens & Yardley in Little Jack Sheppard 31: 🎵 Lord So-and-so bolted with Thingummy’s wife.
1887		Bulletin (Sydney) 22 Oct. 8/4: ‘Then what the eternal thingammy have you got a splay-footed old mud-head of a kanaka digging post-holes on your property for?’ yelped the big elector.
1895		Crowe Aus. Sl. Dict. 85: Thingumy, a general name for anything the name of which you cannot remember.
1898		Binstead & Wells Pink ’Un and Pelican 232: One of the barbed prongs had gone up the left leg, and hitched in the hem of my thingamys.
1900		Sporting Times 27 Jan. 1/3: Tell your mother from me, when you go home, that she must put you on some clean flannel thingamys.
1901		Bateman & LeBrunn [perf. Marie Lloyd] Folkestone for the Day 🎵 Lord and Lady Thingummy la-di-dah-da-ing round the place.
1915		Wodehouse Psmith Journalist (1993) 308: Work, the what’s-its-name of the thingummy and the thing-um-a-bob of the what-d’you-call-it.
1923		Wodehouse Inimitable Jeeves 177: That song of George Thingummy’s.
1932		D.L. Sayers Have His Carcase 305: Here, you, thingummy, speak up, can’t you?
1935		E.F. Benson Mapp and Lucia (1984) 143: The Contessa Thingummy is coming to the Wyses to-morrow.
1939		Franklin & Cusack Pioneers on Parade 79: Lord Thingamy [...] was rather blotto.
1950		A. Buckeridge Jennings Goes To School 169: Two parallel lines with a thingummy going across, sir.
1957		G. Kersh Fowlers End (2001) 127: Keep away from it, young thingumy.
1963–74		B. Humphries Barry McKenzie [comic strip] in Complete Barry McKenzie (1988) 102: I just want to pick up a few personal thingummies.
1978		F. Norman Dead Butler Caper 27: She was in that play with darling Sir Thingummy, with the splendid speaking voice.
1987		P. Muldoon ‘Bechbretha’ in Meeting the British n.p.: a swarm of bees / rolled all its thingamy / into one ball / and lodged in the fork of a tree.
1999		C. Dexter Remorseful Day (2000) 3: I’ll just poke the thingummy, you know, around the four channels.
2000		Indep. Rev. 31 Jan. 1: I shove her in the photo thingamy to have her picture done.

2. the penis [euph. use of sense 1].

1890–1904		Farmer & Henley Sl. and Its Analogues.
1979		J. Morrow Confessions of Proinsias O’Toole 18: And do you know what she did? ... [...] Went out with the Sepoy women after dark ... cut the thingummys off twenty dead wogs! Snip, snip with her secateurs.

3. used as a euph. for an obscenity or curse.

1895

Taranaki Herald (NZ) 12 Oct. 2/9: By blanety blank, if i had a blankety box of thingemy matches, I’d set - world - well on fire.