Conundrum
Pronunciation : Co*nun"drum
Part of Speech : n.
Etymology : [Origin unknown.]
Definition : 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.
Source : Webster's Unabridged Dictionary, 1913