| Solution | Length | |
|---|---|---|
| 4 letters | ||
| dark | 4 | |
| wise | 4 | |
| hard | 4 | |
| deep | 4 | |
| 5 letters | ||
| rough | 5 | |
| spiny | 5 | |
| steep | 5 | |
| black | 5 | |
| tough | 5 | |
| 6 letters | ||
| hidden | 6 | |
| uphill | 6 | |
| subtle | 6 | |
| mental | 6 | |
| arcane | 6 | |
| occult | 6 | |
| wicked | 6 | |
| rugged | 6 | |
| thorny | 6 | |
| secret | 6 | |
| tricky | 6 | |
| severe | 6 | |
| 7 letters | ||
| unknown | 7 | |
| curious | 7 | |
| obscure | 7 | |
| 8 letters | ||
| mystical | 8 | |
| puzzling | 8 | |
| profound | 8 | |
| TOILSOME | 8 | |
| rigorous | 8 | |
| studious | 8 | |
| ticklish | 8 | |
| secluded | 8 | |
| esoteric | 8 | |
| 9 letters | ||
| difficult | 9 | |
| RECONDITE | 9 | |
| scholarly | 9 | |
| intricate | 9 | |
| 10 letters | ||
| undercover | 10 | |
| scholastic | 10 | |
| 11 letters | ||
| underground | 11 | |
| SEQUESTERED | 11 | |
| UNDER WRAPS | 11 | |
| 14 letters | ||
| TRANSCENDENTAL | 14 | |