| hunt(verb, action, study, act, understanding) |
| invention(noun, discovery, finding, spotting, detection) |
| issue(noun, challenge, case, matter) |
| jam(noun, issue, challenge, case, matter) |
| knot(noun, issue, challenge, case, matter) |
| learn(verb, action, study, act, understanding) |
| locate(verb, action, study, act, understanding) |
| matter(noun, issue, challenge, case) |
| mire(noun, issue, challenge, case, matter) |
| mystery(noun, issue, challenge, case, matter) |
| notice(noun, discovery, finding, spotting, detection) |
| nut(noun, issue, challenge, case, matter) |
| perplexer(noun, issue, challenge, case, matter) |
| pickle(noun, issue, challenge, case, matter) |
| pitfall(noun, issue, challenge, case, matter) |
| poser(noun, issue, challenge, case, matter) |
| predicament(noun, issue, challenge, case, matter) |
| problem(noun, issue, challenge, case, matter) |
| puzzle(noun, issue, challenge, case, matter) |
| puzzlement(noun, issue, challenge, case, matter) |