| phenomenon(noun, experience, wonder, fact, occurrence) |
| anomaly(noun, event, experience, puzzle, fact) |
| knotty point(noun, expression, idiom, difficulty, question) |
| vexed question(noun, expression, idiom, difficulty, question) |
| antinomy(noun, question, problem, puzzle, riddle) |
| foolishness(noun, question, problem, puzzle, absurdity) |
| poser(noun, difficulty, question, problem, puzzle) |
| secret(noun, trouble, challenge, question, puzzle) |
| teaser(noun, question, puzzle, riddle) |
| Non sequitur(noun, expression, deception, mistake, error) |
| antithesis(noun, expression, style, reverse, image) |
| catch-22(noun, situation, puzzle, contradiction) |
| disproportion(noun, question, problem, puzzle, variation) |
| disproportionateness(noun, question, problem, puzzle, variation) |
| incompatibility(noun, question, problem, puzzle, riddle) |
| inconsonance(noun, question, problem, puzzle, variation) |
| reversal(noun, question, problem, puzzle, contradiction) |
| difficulty(noun, situation, problem, secret, adversity) |
| brain-teaser(noun, trouble, challenge, question, puzzle) |
| catch(noun, puzzle, absurdity, inconsistency, contradiction) |