| difficult(adjective, hard, great, tough, awkward) |
| daring(verb, adjective, defiant, confronting, defying) |
| ambitious(adjective, ability, importance, effort, main) |
| disputing(verb, adjective, opposing, questioning, disagreeing) |
| exciting(adjective, importance, valuable, main, notable) |
| thought-provoking |
| defying(verb, opposing, disagreeing, confronting, defying) |
| defiant(adjective, unwilling, opposed, defiant, disobedient) |
| formidable(adjective, tough, severe, difficult, awkward) |
| weighty(adjective, importance, valuable, main, notable) |
| bold(adjective, defiant) |
| conflicting(verb, adjective, rival, opposing, defiant) |
| opposing(verb, adjective, rival, opposing, unwilling) |
| provocative(adjective, aggravating) |
| serious(adjective, hard, tough, difficult, importance) |
| audacious(adjective, defiant) |
| consequential(adjective, importance, valuable, main, notable) |
| influential(adjective, importance, valuable, main, notable) |
| key-note(adjective, importance, valuable, main, notable) |
| newsworthy(adjective, importance, valuable, main, notable) |