Green’s Dictionary of Slang

1. trousers.

1794		‘Peter Pindar’ ‘A Rowland for an Oliver’ Works (1794) II 425: I’ve heard, that breeches, petticoats and smock; Give to thy modest mind a grievous shock; And that thy brain [...] Christ’neth them inexpressibles, so nice!
1805		‘Jeremy Swell, Gent.’ Tailors’ Revolt 6: His waistcoat crimson, – and report so tells, / Blue ’twas that grac’d his inexpressibles.
1816		J.H. Lewis Lectures on Art of Writing () 184053: Upon the ship board, wee mee legs doubled up, boggling button holes in any body’s ‘inexpressibles!!!’.
1820		‘Peter Corcoran’ ‘King Tims the First’ in Fancy 18: That single breasted coat, that sweet snub nose, Those inexpressibles: I know the clothes. [Ibid.] 23: Left to the comfort of a tomtit strain, / Pluming my inexpressibles .
1822		New Monthly Mag. 4 88: With a monstrous cocked hat, a sword by his side, and red velvet inexpressibles.
1830		Lytton Paul Clifford I 106: A gentleman [...] having a riding-whip in one hand, and the other hand stuck in the pocket of his inexpressibles.
1832		Egan Bk of Sports 223: The inexpressibles of a Meltonian, are the most expressive things in the world.
c.1840		‘“Taking Off” of Prince Albert’s Inexpressibles’ in C. Hindley Curiosities of Street Lit. (1871) 36: We have [...] Albert toasting-forks, shaving-brushes, and dung-barges, and last, though by no means least, ‘Albert inexpressibles’.
1841		Sun. Flash (NY) 12 Sept. n.p.: He held up the greasy inexpressibles.
1845		Bell’s Life in Sydney 11 Oct. 3/3: Mary Morgan, whose advanced age and general contour, indicated a proficiency and devotion to the pilfering profession that could not be mistaken [was] found with a bran new pair of inexpressibles under her apron.
1850		A.C. Mowatt Fashion I i: Dere’s a pair ob insuppressibles to ’stonish de colored population.
1865		‘Bubble and Squeak’ in Bob Smith’s Clown Song and Joke Bk 31: And a betterer maker of stout inexpressibles, / Never put finger and thumb into shears.
1873		J. O’Connor Wanderings of a Vagabond 142: His nether limbs were encased in a pair of drab inexpressibles.
1882		Dundee Courier (Scot.) 23 June 7/5: A woe-begone spectacle, with the ‘bark’ of his nose, and his ‘inexpressibles’ torn at both knees.
1889–90		Barrère & Leland Dict. of Sl., Jargon and Cant.
1895		Crowe Aus. Sl. Dict. 348: Inexpressibles, trousers.
1897		Truth (London) 10 June 35/1: ‘And the ’ang of his unexpressibles — lor! ’ow them unexpressibles did ’ang’.
1903		Truth (London) 2 Apr. 894/1: [H]e was invariably ‘Braces.’ The allusion was to the suspenders of his inexpressibles, which were always so much in evidence when ho played his favourite game of lawn tennis.
1908		Sun. Times (Perth) 17 May 4/7: Mr Loveskin started the list with a cummerbund and a pair of lavender inexpressibles.
1910		Sun. Times (Perth) 6 Aug. 2nd sect. 12/5: It would seem that Crippen [...] owed his ] capture to the fact that his ‘disguised’ paramour hitched her pants up with safety-pins instead of the regulation braces. The man never lived that held up his inexpressibles with safety-pins.
1928		Exeter & Plymouth Gaz. 7 Mar. 6/6: There was a time when to use the word trousers was almost an indication of a dirty mind. [...] They had been called [...] inexpressibles, indescribables, unwhisperables, mustn’t-mention-ems, sit-upons, sine qua nons, and unutterables.

2. male or female underpants.

1833		Satirist (London) 13 Jan. 435/1: ‘I have put on my drawers (alluding to some warm articles of clothing); for it is inexpressibly cold’.
1833		Satirist (London) 2 June 7/1: A lady-passenger by a Hamburgh steamer [...] smuggled a large quantity of blonde lace in a pair of of inexpressibles.