Green’s Dictionary of Slang

jiminy! excl.

a euph. for Jesus! and used as such in oaths.

1686		D’Urfey Commonwealth of Women Epilogue: Oh jemminy! what is the cause of that?
1694		D’Urfey Comical Hist. of Don Quixote Pt 2 IV i: Ah Gimminy, I could eat the Letter up methinks.
1823		J. Catnach Tom and Jerry’s Rambles Through Paris 1: O! jemminy, you would have laughd ’t see this glorious rout.
1842		‘That’s About the Size of It’ Nancy Dawson’s Cabinet of Songs 26: Oh, jeminy – that’s about the size of it.
1845		B. Webster Miseries of Human Life Act I: Oh! Jeminy! the partridge I left roasting.
1851		Melville Moby Dick (1907) 154: Jimmini, what a squall!
1863		C. Reade Hard Cash I 124: ‘O jiminy!’ This polite ejaculation was drawn out by the speaker’s sudden recognition of Alfred.
1866		Night Side of N.Y. 121: He had just rescued a ‘butt’ from a watery grave in the gutter. ‘Jeminy! don’t chaps about town smoke ’em awful short now’days!’.
1867		Kendal Mercury 9 Mar. 4/2: ‘Oh, jimminy! but you are green’.
1873		E. Eggleston Mystery of Metropolisville 242: Jemeny! they’s five hundred people livin’ on Gray’s claim.
1878		Donaldson Chief (LA) 23 Mar. 1/2: Well then, by Jimminy Pelt, by dad, by hokey, by the long-armed spoon, by jocks.
1880		Besant & Rice Seamy Side II 262: ‘Oh, jeminy!’ says the judge – crafty old man that! – ‘here’s artfulness!’.
1886		Nat. Police Gaz. (NY) 18 Dec. 2/2: Flora Moore [says]: Jimmany jim! Marie Prescott: Drat it!
1888		Iola Register (KS) 21 Dec. 9/5: Santa Claus! Jimminyjinks!
1898		F.W. Hume Hagar of the Pawn-Shop 97: ‘Jiminy!’ said the imp.
1900		Marvel 15 May 15: ‘Jiminy!’ exclaimed Fred.
1900		Marvel 12 Dec. 8: But, jiminy, I’ve got a notion!
1902		A.N. Lyons Hookey 144: An’ – an’ my jimmy! wh-what an ugly copper it was as t-took me away!
1904		St Louis Republican (MO) 5 June 11/1: Oh, my jiminy, she said somsin’ aw-ful!
1905		L. Pound ‘Dialect Speech in Nebraska’ in DN III:i 62: Jeminy, interj. Used like Jehoshaphat.
1908		Marion Dly Mirror (OH) 27 June 12/5: ‘Gee whiz! Jeminy!’ he groaned.
1910		‘O. Henry’ ‘Psyche & the Pskyscraper’ in Strictly Business (1915) 180: Why, Jiminy! we might as well be in New Jersey!
1911		C.E. Mulford Bar-20 Days 29: Yumping Yimminy! Luk at dat fallar!
1927		(con. 1900s) S. Lewis Elmer Gantry 76: Jiminy! You’d go way beyond me!
1930		G. Milburn ‘The Old 99’ Hobo’s Hornbook 175: The old 99 came down the track [...] And she blew – / Key-rist Jim-i-ny how she blew!
1937		R. van Buren ‘Abbie an’ Slats’ [comic strip] Jiminy! What a pan!
1946		B. Cerf Anything For a Laugh 96: ‘Jiminy, Seth,’ screamed a hillbilly bride.
1951		Cusack & James Come in Spinner (1960) 151: Jiminy! This time her drink tasted horrible.
1961		‘Frank Richards’ Billy Bunter at Butlins 4: Oh, crikey! Oh, lor’ Oh, jiminy!
1996		J. Krakauer Into the Wild (1997) 158: ‘Oh, jiminy,’ Stuckey replied.

In exclamations

by jiminy! (also by Jim! by jimminie! by Jimminy! by Jimmy!)

a mild oath, euph. for by Jesus!

1832		S. Lover Legends and Stories 8: ‘By Jaiminee,’ says King O’Toole.
1848		Bartlett Dict. Americanisms 191: jiminy. By Jimmy! An exclamation. Originally, gemini, or the Castor and Pollux of ancient mythology; names by which the old Romans used to swear.
1867		‘F. Kirkland’ Pictorial Bk of Anecdotes 444: By Jim! Major, you got out of that snarl completely — slick! [DA].
1878		J.H. Beadle Western Wilds 611: Went out one fine sunny morning about the first of June, and thought, by jiminy, the whole ground was moving. Ten million hoppers to the square yard.
1884		(con. c.1840) ‘Mark Twain’ Huckleberry Finn 97: And by Jimminy, away down through the texas-hall we see a light!
1896		‘Mark Twain’ Tom Sawyer, Detective Ch. II: By jimminy, it’s int’resting! I’d like to get a look at him.
1898		H. Macilwaine Dinkinbar 32: By Jimmy! Now there you are!
1901		Boy’s Own Paper 6 Apr. 421: Strike him for fifteen thousand, and, by Jimminie! you’ll get it.
1910		O. Johnson Varmint 75: I’ll take my medicine, but I’ll get back at them, by jiminy!
1910		Spokane Press (WA) 27 Mar. 5/3: By jimminee, we’d hunt the town over and over.
1914		S. Lewis Our Mr Wrenn (1936) 178: By jiminy, I will!
1919		D. Runyon ‘A Tale of Two Fists’ XXIV in Pittsburgh Press (PA) 8 June 27/8: ‘My Jiminy, how it hurt!’.
1925		S. Lewis Arrowsmith 169: There – by – jiminy!
1927		N.Z. Truth 29 Dec. 4/6: By Jimminy — You’re beef!
1939		P. Di Donato Christ in Concrete 230: Py yimminy, sissster [sic] has got me ... Yah, she hass.
1947		S.J. Perelman ‘The Customer Is Always Wrong’ Keep It Crisp 105: By jiminy, I’ll padlock the joint!
1967		P. Thomas Down These Mean Streets (1970) 190: I’ll see you on deck, you lousy basturr. By jiminy, I break you just once in half.
1999		K. Sampson Powder 62: By jimminy! This is Hot hot!