| conundrum(expression, difficulty, question, problem) |
| enigma(noun, trouble, challenge, question, puzzle) |
| puzzle(noun, trouble, challenge, question, riddle) |
| teaser(noun, question, puzzle, riddle) |
| vexed question(noun, expression, trouble, challenge, question) |
| brain-teaser(noun, question, puzzle, riddle) |
| brainteaser(noun, question, puzzle, riddle) |
| confusing(noun, question, puzzle, riddle) |
| cruncher(noun, trouble, challenge, question) |
| difficult problem(noun, question, puzzle, riddle) |
| difficulty(noun, trouble, challenge, question) |
| dilemma(noun, trouble, challenge, question) |
| facer(noun, trouble, challenge, question) |
| informalposer(noun, trouble, challenge, question) |
| mind-breaker(noun, question, puzzle, riddle) |
| mystery(noun, trouble, challenge, question) |
| poser |
| problem(noun, trouble, challenge, question) |
| pun(noun, question, puzzle, riddle) |
| puzzlement(noun, question, puzzle, riddle) |