completely unable to understand; utterly confused or perplexed
As we move into 2021, investors are understandably flummoxed about the way forward. (Nehchal Sandhu, Investing In 2021 - Keep It Simple, Businessworld, January 2021)
The thrill of a cryptic clue is in how you are utterly flummoxed at first, and then after staring at it for a few minutes, you see the answer and realise how cunningly it was camouflaged the whole time and how cunning you were to have finally cracked it! (Mihir Balantrapu, Clued In #119 - Enter the charming world of cryptic clues, The Hindu, August 2020)
Germans are flummoxed by humor, the Swiss have no concept of fun, the Spanish think there is nothing at all ridiculous about eating dinner at midnight, and the Italians should never, ever have been let in on the invention of the motor car. (Bill Bryson, Neither Here, Nor There: Travels in Europe)
Werner was flummoxed. He might have a way with words, but understanding a woman was way beyond his capabilities. Shaking his head, he returned to his desk, wondering what he’d done wrong. (Marion Kummerow, From the Ashes)
The word first appears in mainstream English in the middle of the nineteenth century. Charles Dickens is the first writer known to have used it, in his Pickwick Papers: “And my 'pinion is, Sammy, that if your governor don't prove a alleybi, he'll be what the Italians call reg'larly flummoxed, and that's all about it.”
Don't be misled by that reference to Italians, that's just a fancy of old Mr Weller. But there's evidence that the word is older in Scots and English dialects, in the same sense that we use it now, to be bewildered, perplexed, or puzzled, or to defeat or overcome somebody in argument (“That fair flummoxed 'im!”). At one time, Americans sometimes used it in the sense of failing or being defeated and so being exhausted or beaten, but that sense seems to have died out.
There's also the English dialect flummock, at one time known from Yorkshire down to Gloucestershire, to go about in a slovenly or untidy manner, or to make things untidy, or to confuse, which may be a slightly older version of the same word. It might also be linked to lommock or lummox, a clumsy or stupid person, known from the same area.
That's where the trail runs cold. The suggestion is that all these words are in some degree imitative of the noise of throwing things down noisily or untidily, so it may be associated with another dialect word flump, a heavy or noisy fall. (World Wide Words)
from flummox; 1837, cant word, also flummux, of uncertain origin, probably risen out of a British dialect (OED finds candidate words in Herefordshire, Gloucestershire, southern Cheshire, and Sheffield). 'The formation seems to be onomatopœic, expressive of the notion of throwing down roughly and untidily.' [OED]. (Online Etymology Dictionary)