| Solution | Length | |
|---|---|---|
| 4 letters | ||
| hard | 4 | |
| 5 letters | ||
| spiny | 5 | |
| sheer | 5 | |
| rough | 5 | |
| tough | 5 | |
| rocky | 5 | |
| steep | 5 | |
| stiff | 5 | |
| lofty | 5 | |
| tight | 5 | |
| 6 letters | ||
| wicked | 6 | |
| uphill | 6 | |
| easier | 6 | |
| trying | 6 | |
| thorny | 6 | |
| rugged | 6 | |
| severe | 6 | |
| tricky | 6 | |
| 7 letters | ||
| stickle | 7 | |
| serious | 7 | |
| onerous | 7 | |
| testing | 7 | |
| 8 letters | ||
| rigorous | 8 | |
| steepens | 8 | |
| terrible | 8 | |
| GRUELING | 8 | |
| TOILSOME | 8 | |
| strained | 8 | |
| ticklish | 8 | |
| 9 letters | ||
| wearisome | 9 | |
| difficult | 9 | |
| punishing | 9 | |
| gruelling | 9 | |
| strenuous | 9 | |
| laborious | 9 | |
| 11 letters | ||
| precipitous | 11 | |
| precipitate | 11 | |
| troublesome | 11 | |
| 12 letters | ||
| backbreaking | 12 | |