riddle
n. countable B2 Upper Intermediate US //ˈɹɪdəɫ// UK //ɹˈɪdəl// rid·dle
n. a puzzle or a difficult question that uses clever language to hide the answer. You have to think creatively to solve it.
n. a question or statement intentionally phrased with double meanings or obscure metaphors, requiring ingenuity to solve. Often used to describe a person or situation that is difficult to understand.
The children spent the afternoon asking each other every riddle they knew.
The detective realized that the killer's note was actually a riddle pointing to the next location.
To the historians, the sudden disappearance of the settlement remains a riddle, as no physical evidence of conflict or disease has ever been recovered from the site.
Usage
Often paired with the verbs 'solve', 'crack', or 'unravel'.