| Solution | Length | |
|---|---|---|
| 4 letters | ||
| sure | 4 | |
| same | 4 | |
| rapt | 4 | |
| true | 4 | |
| 5 letters | ||
| solid | 5 | |
| rigid | 5 | |
| sound | 5 | |
| 6 letters | ||
| trusty | 6 | |
| torpid | 6 | |
| secure | 6 | |
| static | 6 | |
| steady | 6 | |
| strong | 6 | |
| stable | 6 | |
| 7 letters | ||
| certain | 7 | |
| staunch | 7 | |
| 8 letters | ||
| resolute | 8 | |
| tireless | 8 | |
| unfading | 8 | |
| reliable | 8 | |
| stubborn | 8 | |
| SEDULOUS | 8 | |
| UNTIRING | 8 | |
| surefire | 8 | |
| constant | 8 | |
| 9 letters | ||
| unchecked | 9 | |
| steadfast | 9 | |
| true-blue | 9 | |
| unaltered | 9 | |
| UNDAUNTED | 9 | |
| UNWEARIED | 9 | |
| tenacious | 9 | |
| REMAINING | 9 | |
| UNVARYING | 9 | |
| foolproof | 9 | |
| sleepless | 9 | |
| sustained | 9 | |
| perpetual | 9 | |
| quiescent | 9 | |
| 10 letters | ||
| UNFLAGGING | 10 | |
| stationary | 10 | |
| UNSWERVING | 10 | |
| UNWAVERING | 10 | |
| relentless | 10 | |
| purposeful | 10 | |
| UNCHANGING | 10 | |
| 11 letters | ||
| trustworthy | 11 | |
| undestroyed | 11 | |
| SUBSTANTIAL | 11 | |
| unfaltering | 11 | |
| unflinching | 11 | |
| UNREMITTING | 11 | |
| predictable | 11 | |
| preoccupied | 11 | |
| unrelenting | 11 | |
| 12 letters | ||
| UNCHANGEABLE | 12 | |
| 13 letters | ||
| INEXHAUSTIBLE | 13 | |
| UNCONQUERABLE | 13 | |
| UNINTERRUPTED | 13 | |
| well-grounded | 13 | |
| single-minded | 13 | |