Green’s Dictionary of Slang

1. (also umptysteen, umptysteenth, umpty-umpth, umptillion) of an indefinite number, usu. a large one, in combs., e.g. umpty-nine, umpty-eleven; thus umptieth [umpteen adj.].

1886		Riverine Grazier (Hay, NSW) 2 Jan. 1/7: ‘What is your profession?’ ‘An actress of the French comedy.’ ‘What is your age!’ ‘Umpty years’.
1886		Salt Lake Herald 25 Apr. 6: An Ohio editor vaguely says an exchange has enlarged avout ‘about umpty-ump inches’.
1887		Electrical Review (NY) 3 Sept. 6: ‘Wait for umpty-umpty-steen!’ / Central orders and i lean / Up against the wall.
1912		T.A. Dorgan Daffydils 23 Nov. [synd. cartoon strip] The little darlings were out bird-nesting. they had already collected umpty sprain of them.
c.1912		Powell & Arthurs [perf. Marie Lloyd] Three Ages of Women 🎵 Great, oh, she’s great, is the woman of umpty-eight.
1916		P. MacGill The Great Push 150: When I go back to blighty I’ll go to bed and I’ll not get up for umpty-eleven months.
1923		Kipling ‘A Friend of the Family’ in Debits and Credits (1926) 316: So, you see, the bettin’ was even on my drawin’ a V.C. or getting Number Umpty rest-camp or — a firing party before breakfast.
1948		Wash. Post (DC) 20 June 1L: Victo Mature, who vowed umptillion times he’d never show off his muscles again [etc].
1949		L. Pound ‘Miscellany: Indefinite Numbering’ in AS XXIV:3 229: umptysteen. ‘Perhaps umptysteen democrats voted for it.’ — Heard orally. umptysteenth. ‘The umptysteenth man was a dyed-in-the-wool againster.’ — Radio commentator.
1970		Time 7 Dec. 74: He is now two-thirds through his umpty-umpth cycle of the 32 Beethoven sonatas.

2. unpleasant, difficult [? get the hump under hump n.¹ ].

1914		Bulletin (Sydney) 16 July 40/1: The Liberal outlook in Queensland is umpty. The P.P.L. has been battling to secure candidates to carry Joe Cook’s tattered banner in the impending rough-up, but there is a decided dearth of candidates.
1925		(con. WWI) Fraser & Gibbons Soldier and Sailor Words 294: Umpty Iddy, To Feel: So so. Not very well. All upside down.
1938		G. Kersh Night and the City 34: ‘How’s things?’ ‘Pretty umpty.’.
1943		R. Llewellyn None But the Lonely Heart 39: Madame La Zaka, a very umpty bit of stuff.
1972		Galton & Simpson ‘Man of Letters’ Steptoe and Son [TV script] It was a bit umpty.

3. impoverished.

1979

(con. 1920s) J. White ‘Campbell Bunk’ in History Workshop 26: A rich vein of slang which harked back to an older London street culture [...] Words which were not current in ordinary working-class speech [...] crampy - and umpty - (money is scarce) .