| audit(noun, search, discovery, exploration) |
| brainteaser(noun, challenge, question, task) |
| catch(noun, challenge, question, task) |
| challenge(noun, search, discovery, exploration) |
| check(noun, search, discovery, exploration) |
| checkup(noun, search, discovery, exploration) |
| conundrum(noun, challenge, question, task) |
| corner(noun, challenge, question, task) |
| cross-examination(noun, search, discovery, exploration) |
| crux(noun, challenge, question, task) |
| delving(noun, search, discovery, exploration) |
| diagnosis(noun, search, discovery, exploration) |
| dilemma(noun, challenge, question, task) |
| disquisition(noun, search, discovery, exploration) |
| enigma(noun, challenge, question, task) |
| examen(noun, search, discovery, exploration) |
| examination(noun, search, discovery, exploration) |
| feeler(noun, search, discovery, exploration) |
| fix(noun, challenge, question, task) |
| glitch(noun, challenge, question, task) |