Green’s Dictionary of Slang

dag n.3

a euph. for God, usu. in combs. e.g. dag on, dag gone, dag-gum, dag nab; also euph. of damn! excl. (1)

Kansas University Quarterly (Ser. B) VI 86: Dag on: dog on. A mild oath.
[US]DN III 117: Dag gone [...] A mild oath. ‘Dag gone it.’.
[US]L.W. Payne Jr ‘Word-List From East Alabama’ in DN III:iv 304: dag bust it, interj. An expletive.
[US]G. Herriman ‘Baron Bean’ [comic strip] This giant fire-cracker ought to bring that scoundrel to the surface, dagnab him!
[US]Jerry on the Job [comic strip] Daggunit! Daggunit!
[US]Chicago Trib. 26 May 8/3: Dagnabit! [Ibid.] Dagnab – Dawg gone – Who in the heck is this ’ere F.F. an’ what right has he to glaum my writin’ efforts.
[US]H.B. Parks ‘Southwestern Lore IX’ in Botkin (1944) 15–26: ‘Dag gum,’ says Dave.
[US]G. Milburn No More Trumpets 67: Dag gum bathroom smells just like a hen coop.
in J.S. Hall Sayings Old Smoky (1972) 54: You mighty dag-gone right I would!
[US]W. Guthrie Seeds of Man (1995) 258: I’m a thinkin’ about layin’ somethin’ a whole lot warmer an’ pertier th’n a dag-rattened old muddy brick.
[US]Mad mag. Jan.–Feb. 30: Dagnab cash box still won’t open!
[UK]Oh Boy! No. 18 9: Dag-a-dag! The varmint’s snuck under cover.
[US]Mad mag. May 6: By dag! Let’s face it! We ain’t big-time!
[US] in DARE.
[UK]A-Team Storybook 58: These dagblasted aerial machines are enough to drive any man crazy.
[US]Eble Campus Sl. Spring 3: dag – expression of surprise or disbelief.
[US]L. Pettiway Workin’ It 108: I was like ‘Dag, Mom!’.
[US]College Sl. Research Project (Cal. State Poly. Uni., Pomona) 🌐 Dagger (int.) An exclamation used when you’ve received bad news (syn. = darn).
[US]Hope College ‘Dict. of New Terms’ 🌐 dagnabbit int. A term of frustration. [...] ‘Well dagnabbit, it’s all out of paper.’.
[US]P. Beatty Tuff 16: Dag, Fariq, you right, my sperms is fizzing.
[US]J. Stahl Plainclothes Naked (2002) 239: ‘Dag nab it,’ Tony chuckled. ‘I think we came at a bad time!’.
Burns & Overmyer ‘Margin of Error’ Wire ser. 4 ep. 6 [TV script] Dag! [...] I’m in enough trouble with Miss Anna as it is.
[US]C. Eble UNC-CH Campus Sl. Spring 2016 3: DAGGUM! — damn! Favorite euphemism of UNC men’s basketball coach Roy Williams: ‘Box out on free throws! Daggum!’.
[US]J. Hannaham Didn’t Nobody Give a Shit 49: Oh, dag, ridin this bitch [i.e. a subway] feel ezzackly the same’s it always did.