Language Hat’s use of this in the 1905 words thread prompted me to check the etymology. It’s such a lovely word and I was not surprised to see from the OED that it was probably of English dialectal origin. I could well imagine it in the mouths of Devonshire yokels of my youth, ‘Er were proper flummoxed. Well, not quite Devonshire, but I see Gloucestershire is one of the counties referenced in the OED entry so not too far afield.
Etymology: probably of English dialectal origin; compare flummocks to maul, mangle ( Heref. Gloss. 1839), flummock slovenly person, also hurry, bewilderment, flummock to make untidy, disorder, to confuse, bewilder (see various E.D.S. glossaries, Heref., Glouc., S. Cheshire, Sheffield). The formation seems to be onomatopoeic, expressive of the notion of throwing down roughly and untidily; compare flump , hummock , dialect slommock sloven.
Delightful to see that the earliest cite is from Pickwick Papers (one of those books that whenever you see mentioned you want to rush right back and read it all over again).
1837 Dickens Pickwick Papers xxxii. 345 He’ll be what the Italians call reg’larly flummoxed.
BTW here’s one of those wonderful discoveries you often come across in OED when your eye glances across to neighbouring words. I’ve never come across this American term before. I see that the latest cite in the nonsense meaning is 1941. Is the term still current for either the dish or the other sense?
Etymology: probably arbitrarily < flummery n.
1. (See quot.)
1872 M. Schele de Vere Americanisms 338 Flummadiddle‥consists of stale bread, pork-fat, molasses, cinnamon, allspice, [etc.]; by the aid of these materials a kind of mush is made, which is baked in the oven and brought to the table hot and brown.
2. slang. Nonsense, humbug; also, something trivial or ridiculous.
1850 in H. Wentworth Amer. Dial. Dict. (at cited word), Fuma~diddle, flummydiddle.
1854 M. J. Holmes Tempest & Sunshine iv. 51 What does she want of any more flummerdiddle notions?
1941 Sat. Evening Post 25 Oct. 35/3 An’ does you try any fuma~diddles, you is right away gwine happen to a catastrophe.