come a cropper

Possibly from the phrase neck and crop, in which crop may refer to the backside of a horse.

• "She came a cropper on the stairs and broke her leg."
• "I should feel certain that I should come a cropper, but still I'd try it. As you say, a fellow should try."
• "You couldn't help feeling he'd be caught out one day, and then what an almighty cropper he'd come!"
• "We are accustomed to seeing Morphy conquer brilliantly against great odds; but this time he comes a cropper."
• "You tried to convey too much and you conveyed nothing. You came a cropper, major."
• "We had been taught Latin, French and German grammar; but English grammar was something we felt we were expected to infer from our reading – which is doubtless why I came a cropper over “its” and “it’s”."
• "Although they were meant to reach the Moon no matter what, cryptocurrencies are also coming a cropper."

• neck and crop