Green’s Dictionary of Slang

a euph. for Jesus! or Jesus Christ! and as such a mild excl.

1878		A.F. Mulford Fighting Indians 7: Gee Whiz!
1885		W.T. Gray Bad Boy at Home 8: Gee wiz [DA].
1887		Wichita Eagle (KS) 23 Oct. n.p.: ‘Jee whizz!’ exclaimed the Old Settler.
1889		Salt Lake Herald (UT) 16 July 4/4: Gee-whiz! Ow! Wow! Where am I?
1897		O. Wister Lin McLean 107: ‘Gee whiz!’ said Barker, briskly.
1898		H.H. Lewis A Gunner Aboard the ‘Yankee’ 68: ‘Gee whiz!’ said the ‘Kid’.
1900		Sporting Times 9 June 1/5: Gee whiz! [...] you look fierce.
c.1900		Ford & Bratton [perf. Marie Lloyd] Just as if she didn’t know 🎵 Now tell me why that man should say, ‘Gee whizz, but that’s a beaut’.
1904		Sydney Sportsman (Surry Hills, NSW) 27 Jan. 3/4: Geewhiz, and likewise Geewhitaker, Jehoram, Jehosaphat!
1906		J.W. Carr ‘Words from Northwest Arkansas’ in DN III:ii 137: gee fuzz, interj. Goodness! A mild exclamation.
1907		Globe (London) 9 July 1/4: A small boy distinctly ejaculated, W‘hat ho!’ ‘Ghee-whiz!’ replied the Earl.
1909		Gem 6 Feb. 23: Gee-whizigig!
1910		Sun. Times (Perth) 30 Jan. 2nd sect. 4/7: Great Scott! Gadzooks! Gee-whizz!
1917		A. Wright diary 19 July in Muddy France (1988) 11: Feel somewhat better today, but yesterday, gee whizz . . . !
1919		Colonist (Nelson, NZ) 15 Oct. 4/3: ‘Jee wiz, what a lot of issues will go before the electors,’ sez Mumbles.
1920		Bulletin (Sydney) 12 Feb. 28/2: ‘Gee Whiz’; No doubt it is very noble of Arthur Robinson, Vic. Attorney-General, to go to England at his onw expense.
1921		N. Putnam West Broadway 130: ‘Gee whiz! They’re looking for Tom as well!’.
1922		S. Lewis Babbitt (1974) 63: Aw, gee whiz, if the Doppelbraus can afford a closed car, I guess we can!
1928		C. McKay Home to Harlem 198: Geewizard! [...] Tell ’em next time not to ring the fire alarm so loud.
1934		T. Wood Cobbers 81: ‘Gee-whiz!’ said Malcolm.
c.1943		S .J. Baker Aus. Vulgarisms [t/s] 6: Jesus: Jeez, jeewizz, gee, jiminy, by Jove, by George, by jingo, by jingies, jericho, jerusalem. [added in pencil: Jiminy Cricket.
1945		Look (advert for Nescafé) 18 Sept. 10: His aide quickly stirred up a cup of Nescafé, then said ... ‘Well sir, try this!’ He did ... stared in amazement ... and yelled, ‘Gee whiz!’.
1955		B. Schulberg On the Waterfront (1964) 97: Well, gee whizz, ya don’t hafta blow ya stack about it!
1967		(con. 1920s) J. Thompson South of Heaven (1994) 164: Well now, gee whiz, by ding!
1971		B. Moyers Listening to America 178: Gee whiz, this is something you’ve just got to save.
1989		Dandy Comic Library No. 142 21: Gee whizz! That sneeze has started an avalanche!
1998		(con. 1960s) G. Washington Blood Brothers 76: Gee fucking whiz.
2005		J. Holtzman Hist. of Baseball Scribes 13: [Ch. heading] Aw Nuts vs Gee Whiz.
2011		J.J. DeCeglie Drawing Dead [ebook] I had a bag packed before you could say ‘Gee Whiz’.
2023		D. Whish-Wilson I Am Already Dead 258: ‘[G]ee whiz and Jiminy Crickets, what a terrific shot, eh?’.