| going-over(noun, search, discovery, exploration) |
| gordian knot(noun, challenge, question, task, expression) |
| grilling(noun, search, discovery, exploration) |
| hearing(noun, search, discovery, exploration) |
| hitch(noun, challenge, question, task) |
| hole(noun, challenge, question, task) |
| hot water(noun, challenge, question, task, expression) |
| inquest(noun, search, discovery, exploration) |
| inquiry(noun, search, discovery, exploration) |
| inquisition(noun, search, discovery, exploration) |
| inspection(noun, search, discovery, exploration) |
| interrogation(noun, search, discovery, exploration) |
| investigation(noun, search, discovery, exploration) |
| issue(noun, challenge, question, task) |
| jam(noun, challenge, question, task) |
| mire(noun, challenge, question, task) |
| mystery(noun, challenge, question, task) |
| perplexer(noun, challenge, question, task) |
| pickle(noun, challenge, question, task) |
| pitfall(noun, challenge, question, task) |