| Solution | Length | |
|---|---|---|
| 4 letters | ||
| shut | 4 | |
| snug | 4 | |
| 5 letters | ||
| tight | 5 | |
| taped | 5 | |
| 6 letters | ||
| closed | 6 | |
| signed | 6 | |
| virgin | 6 | |
| unopen | 6 | |
| 7 letters | ||
| settled | 7 | |
| stamped | 7 | |
| unknown | 7 | |
| staunch | 7 | |
| strange | 7 | |
| ensured | 7 | |
| 8 letters | ||
| ratified | 8 | |
| unopened | 8 | |
| RECEIVED | 8 | |
| promised | 8 | |
| airtight | 8 | |
| puzzling | 8 | |
| SWORN TO | 8 | |
| 9 letters | ||
| WINDPROOF | 9 | |
| warranted | 9 | |
| professed | 9 | |
| untouched | 9 | |
| unplumbed | 9 | |
| lacquered | 9 | |
| unbeknown | 9 | |
| UNEXPOSED | 9 | |
| validated | 9 | |
| uncharted | 9 | |
| 10 letters | ||
| unfamiliar | 10 | |
| UNEXPLORED | 10 | |
| unfathomed | 10 | |
| unheard-of | 10 | |
| RECOGNIZED | 10 | |
| PRIVILEGED | 10 | |
| stipulated | 10 | |
| waterproof | 10 | |
| undertaken | 10 | |
| UNKNOWABLE | 10 | |
| watertight | 10 | |
| unrevealed | 10 | |
| 11 letters | ||
| UNDISCLOSED | 11 | |
| UNPERCEIVED | 11 | |
| UNEXPLAINED | 11 | |
| unsuspected | 11 | |
| 12 letters | ||
| unclassified | 12 | |
| UNIDENTIFIED | 12 | |
| UNDISCOVERED | 12 | |
| 14 letters | ||
| undiscoverable | 14 | |