Co‐nun″drum (?), n. 1. A kind of riddle based upon some fanciful or fantastic resemblance between things quite unlike; a puzzling question, of which the answer is or involves a pun.
Or pun ambiguous, or conundrum quaint.
J. Philips.
2. A question to which only a conjectural answer can be made.
Do you think life is long enough to let me speculate on conundrums like that?
W. Black.