Examples from the Web for stumper
"I thought it was a stumper," he remarked with evident satisfaction.The Land of Promise|D. Torbett
This logic was rather a stumper; but they took him up, as before said, and carried him for further examination.The Women of the Confederacy|J. L. Underwood
That was a 'stumper' for the poor woman, who evidently did not understand one half of the sentence.
That was a "stumper" for the poor woman, who evidently did not understand one-half of the sentence.Among the Pines|James R. Gilmore
It wur a stumper to Sally, so she got Jess to explain it, and the way he did it was enormous.