Green’s Dictionary of Slang

(US) a general excl. of pleasure or surprise.

1906		‘Dream of the Rarebit Fiend’ in Eve. Telegram (N.Y.) 20 Sept. 6/3–5: HOD DIGGETTY. THEY’RE SWELL! HOT DOG! JUST THE THING! EH. THEY FEEL GREAT! HOT DIGGETTY! WHEE!
1913		Fort Wayne Sentinel 4 June 8/5: ‘Didn’t you hear me say ‘hod dickety dog?’ asked the traveler. ‘What’s the matter with you rubes, anyway. Everybody who is anybody knows that that means I’m jerry; I’m hep; I connect.’.
1922–24		O.O. McIntyre White Light Nights 103: ‘Hot diggedy dog!’ he exclaimed.
1928		M. Bodenheim Georgie May 28: Diggedy dog, ah wish you’d brained her! [Ibid.] 103: Hot jiggety, if Dopey did fo’ Mike they’ll shuah puy youah behind in the jug.
1929		M. Levin Reporter 54: She was rerouging her lips. (Drawing by John Held, Jr.) Hot Diggity!
c.1940		‘Tillie & Mac with Mr Simpkins and Bubbles’ [comic strip] in B. Adelman Tijuana Bibles (1997) 24: Hot diggins Bubbles you’re sure a sweet lay.
1957		(con. 1944) A. Myrer Big War 243: Hot diggerty damn.
1963		G. Lambert Inside Daisy Clover (1966) 61: Hot-Diggity-Dog! It’s beautiful! It really is!
1964		N.B. Harvey Any Old Dollars, Mister? 127: They jest appeared – hot diggerty! Like that! And he snapped his fingers.
1969		B. Beckham My Main Mother 39: Hot diggity. Sakes and shakes, pow-wow coon box and lickerty rickerty split for hearts and dales hooray.
1991		Desperate Dan Special No. 7 19: Hot-Diggety! You’d be mighty desperate to eat that!
1997–2001		Online Sl. Dict. 🌐 dank [...] adj 1. very good, excellent; COOL. Note: commonly used in the phrase ‘Diggity dank!’.
2001		Guardian G2 27 June 3: What the hotdiggery is going on?
2012		E. Petulengro Caravans & Wedding Bands 181: He’d come to see me [...] about his penchant for dressing up in woman’s clothes! Hot diggity dog!