| Solution | Length | |
|---|---|---|
| 4 letters | ||
| hard | 4 | |
| 5 letters | ||
| spiny | 5 | |
| rigor | 5 | |
| tough | 5 | |
| stern | 5 | |
| rough | 5 | |
| steep | 5 | |
| needy | 5 | |
| rigid | 5 | |
| 6 letters | ||
| severe | 6 | |
| asking | 6 | |
| strict | 6 | |
| strait | 6 | |
| taxing | 6 | |
| subtle | 6 | |
| tricky | 6 | |
| rugged | 6 | |
| thorny | 6 | |
| uphill | 6 | |
| urgent | 6 | |
| wicked | 6 | |
| trying | 6 | |
| 7 letters | ||
| arduous | 7 | |
| precise | 7 | |
| weighty | 7 | |
| onerous | 7 | |
| spartan | 7 | |
| exigent | 7 | |
| teasing | 7 | |
| refined | 7 | |
| 8 letters | ||
| INNEEDOF | 8 | |
| exacting | 8 | |
| TOILSOME | 8 | |
| punctual | 8 | |
| PRESSING | 8 | |
| rigorous | 8 | |
| ticklish | 8 | |
| 9 letters | ||
| stringent | 9 | |
| strenuous | 9 | |
| selective | 9 | |
| squeamish | 9 | |
| punishing | 9 | |
| unsparing | 9 | |
| INSISTING | 9 | |
| religious | 9 | |
| insistent | 9 | |
| WHEEDLING | 9 | |
| 10 letters | ||
| scrupulous | 10 | |
| 11 letters | ||
| punctilious | 11 | |
| challenging | 11 | |
| 14 letters | ||
| superincumbent | 14 | |