Green’s Dictionary of Slang

flummox v.

also flummix, flummux
[? dial. flummocks, to maul, to mangle; flummock n., a slovenly person or flummock v., to make untidy, to disorder, to confuse, to bewilder + onomat. element based on throwing down roughly and untidily. As such, the term is reminiscent of flump, a hummock, and slommock, a sloven]

1. (US) to blunder, to fail; to die.

[US]B.H. Hall College Words (rev. edn) 205: flummux. To fail; to recite badly.
[US]Schele De Vere Americanisms 602: Flummux, to, a slang term used in England in the sense of to hinder, to perplex, denotes in America the giving up of a purpose, and even to die.
[US]M.G. Hayden ‘Terms Of Disparagement’ in DN IV:iii 203: flummox, in colleges applied to a poor recitation. ‘I went flummox this morning in German.’.

2. to back down, to back out of a promise; to disappoint; to opt out of a round of betting.

[UK]‘Poll Tomkinson’ in Convivialist in Spedding & Watt (eds) Bawdy Songbooks (2011) IV 15: To be true, so help your bob, you swore, / But you’ve flummux’d me now, Poll Tomkinson.
[US]N.Y. Clipper 28 May 1/3: ‘Down with your dust, I say. [The bettor hesitates.] Do you flunk out, then?’ ‘Yes, I flummux this time...’.
[UK]J. Mair Hbk of Phrases 105: Flummux, to give up a purpose.
[UK]E. Pugh Cockney At Home 256: What I suggest [...] is that our old and tried – but never convicted – friend, Billy Westerton, trots out one of his well-known comics, and be flummoxed to all debatin’!
[US]L. Weiner ‘Further Word-Lists – New Hampshire’ in DN IV:ii 154: flummux, v. To back out of a trade.

3. (also flummax) to fool, to confuse, to overcome (by trickery).

[UK] ‘Mrs. Jones’ in Delicious Chanter 31: Joe own’d he was flummix’d and diddled at last.
[UK] ‘The Bastard’s Christening’ in Comic Songster and Gentleman’s Private Cabinet 14: Our appetites you flummux.
[UK]New Sprees of London 36: [T]he gulpin must have his ogles about him, or he will be flummuxed.
[US]J.M. Field Drama in Pokerville 73: ‘Prehaps,’ Parson Hyme didn’t put it into Pokerville for two mortal hours; and prehaps Pokerville didn’t wiggle, wince, and finally ‘flummix’ right beneath him!
[US]W.C. Hall ‘Mike Hooter’s Bar Story’ Spirit of the Times 26 Jan. (N.Y.) 581: I thought I should er flummoxed!
[UK]Hotten Dict. of Modern Sl. etc. 41: FLUMMUX, to perplex, hinder.
[UK]Worcs. Chron. 8 June 4/5: I'll drop the plebian (for Lords should consort), / If you join me, and flummox Lord D. and the court.
[UK] letter to Editor Daily News 25 Sept. 5/1: Did the driver think to flummox us by his lip because he thought we weren’t fly to him?
[UK]Sportsman (London) 5 Aug. 2/1: Notes on News [...] At last the Poor-law Board have been ‘flummaxed’.
[UK]G.R. Sims Dagonet Ballads 103: Ev’ry man in the force here knows Molly—there’s pretty good reasons he should— / For the privates and sergeants and ’spectors, she flummoxed ’em all to a coon.
[UK] ‘’Arry in Switzerland’ in Punch 5 Dec. in P. Marks (2006) 98: My larf was sometimes a bit late, / And so flummoxed the Frenchies a few.
[UK]E.W. Hornung Amateur Cracksman (1992) 30: We shall probably get in without any difficulty at all; it’s the getting out again that may flummox us.
[UK]Marvel III:53 5: So Montbois [...] means a good deal, too, I should say ter judge by the way that little note flummoxed yer!
[UK]C. Holme Lonely Plough (1931) 162: He said he was there to see that the poor were not being fleeced by a flummoxing farmer.
[UK]Breton & Bevir Adventures of Mrs. May 48: What flummoxed me when I went, was as I still ’adn’t another ’ome to go to.
[UK]N. Gale ‘Baffled’ in Close of Play 29: You can bet your income, Jake, / The like of this has not been known since oily Aaron’s rod / Completely flummoxed Pharaoh by its appetite for snake.
[Scot]Sun. Post (Dundee) 9 May 9/4: [headline] The Aussies Know One Thing Can Flummox Them.
[Aus]D. Stivens Scholarly Mouse and other Tales 17: A greyhound flummoxed me out of eight and a half.
[UK]P. Bailey An Eng. Madam 100: I said, ‘he’s dead normal even though he’s dressed as a woman.’ That flummoxed him, I can tell you.
[NZ]A. Duff One Night Out Stealing 33: Flummoxed. Stumped the lot of the dunderhead boobheads.
R. Wainwright Lost Boy 88: Clinton was a more complex character, devouring science books [...] to devise questions he thought would flummox the adults.
[US]P. Beatty Sellout (2016) 67: That madcap posse of street urchins who [...] flummoxed potbellied coppers.

4. to knock out.

E.H. Shackleton ‘Shellback’ in Aurora Australis n.p.: And his body was lusty and strong as that of a young man, for could he not with one biff, which is to say, sallikatowzer, of his clenched hand, totally flummax, or in the modern tongue, put to sleep, a fullgrown and stalwart man.