| Solution | Length | |
|---|---|---|
| 3 letters | ||
| icy | 3 | |
| 4 letters | ||
| grim | 4 | |
| dour | 4 | |
| nogo | 4 | |
| tabu | 4 | |
| 5 letters | ||
| taboo | 5 | |
| stern | 5 | |
| no-go | 5 | |
| 6 letters | ||
| severe | 6 | |
| banned | 6 | |
| vetoed | 6 | |
| barred | 6 | |
| 7 letters | ||
| austere | 7 | |
| ominous | 7 | |
| tabooed | 7 | |
| illicit | 7 | |
| illegal | 7 | |
| 8 letters | ||
| verboten | 8 | |
| unlawful | 8 | |
| 9 letters | ||
| unallowed | 9 | |
| 10 letters | ||
| prohibited | 10 | |
| UNLICENSED | 10 | |
| proscribed | 10 | |
| 11 letters | ||
| UNTOUCHABLE | 11 | |
| 12 letters | ||
| unauthorized | 12 | |
| unsanctioned | 12 | |
| 13 letters | ||
| UNMENTIONABLE | 13 | |