| cross(noun, trouble, hard, blow, difficulty) |
| endeavor(noun, performance, action, go, work) |
| endeavour |
| experience(noun, action, understanding, knowledge, practice) |
| experimentation(noun, study, measure, examination, test) |
| irritant(noun, trouble, bother, strain, difficulty) |
| probation(noun, check, approval, examination, test) |
| probative(adjective, experimental) |
| provisional(adjective, new, unsettled, indefinite, untried) |
| standard(noun, check, rule, process, approval) |
| tragedy(noun, trouble, ruin, blow, distress) |
| audition(noun, ability, examination, test, experiment) |
| determination(noun, energy, struggle, exertion, sweat) |
| drag(noun, trouble, bother, strain, difficulty) |
| exploratory(adjective, new, opening, unsettled, basic) |
| hell(noun, place, difficulty, situation, grave) |
| hit-or-miss(adjective, experimental) |
| irritation(noun, trouble, bother, concern, strain) |
| match(noun, event, fight, challenge, struggle) |
| nightmare(noun, trouble, experience, torment, vision) |