| Solution | Length | |
|---|---|---|
| 3 letters | ||
| vow | 3 | |
| 4 letters | ||
| cuss | 4 | |
| UPON | 4 | |
| oath | 4 | |
| sign | 4 | |
| aver | 4 | |
| seal | 4 | |
| avow | 4 | |
| 5 letters | ||
| curse | 5 | |
| vouch | 5 | |
| swear | 5 | |
| 6 letters | ||
| ratify | 6 | |
| attest | 6 | |
| second | 6 | |
| affirm | 6 | |
| pledge | 6 | |
| 7 letters | ||
| warrant | 7 | |
| testify | 7 | |
| support | 7 | |
| 8 letters | ||
| validate | 8 | |
| sanction | 8 | |
| 9 letters | ||
| undersign | 9 | |
| 10 letters | ||
| UNDERWRITE | 10 | |
| 12 letters | ||
| subscribe-to | 12 | |
| RUBBER STAMP | 12 | |