| Solution | Length | |
|---|---|---|
| 4 letters | ||
| hard | 4 | |
| numb | 4 | |
| cold | 4 | |
| 5 letters | ||
| brute | 5 | |
| stony | 5 | |
| rough | 5 | |
| tough | 5 | |
| rocky | 5 | |
| crass | 5 | |
| cruel | 5 | |
| stoic | 5 | |
| 6 letters | ||
| unfelt | 6 | |
| unkind | 6 | |
| severe | 6 | |
| frigid | 6 | |
| savage | 6 | |
| 7 letters | ||
| stoical | 7 | |
| callous | 7 | |
| unmoved | 7 | |
| robotic | 7 | |
| 8 letters | ||
| SOULLESS | 8 | |
| pitiless | 8 | |
| sluggish | 8 | |
| ruthless | 8 | |
| UNLOVING | 8 | |
| hardened | 8 | |
| 9 letters | ||
| impassive | 9 | |
| unnatural | 9 | |
| insensate | 9 | |
| senseless | 9 | |
| heartless | 9 | |
| 10 letters | ||
| INSENSIBLE | 10 | |
| relentless | 10 | |
| withdrawal | 10 | |
| unmerciful | 10 | |
| UNYIELDING | 10 | |
| spiritless | 10 | |
| 11 letters | ||
| indifferent | 11 | |
| COLDBLOODED | 11 | |
| insensitive | 11 | |
| UNFORGIVING | 11 | |
| emotionless | 11 | |
| UNTOUCHABLE | 11 | |
| remorseless | 11 | |
| unemotional | 11 | |
| thick skin | 11 | |
| hardhearted | 11 | |
| unconscious | 11 | |
| coldhearted | 11 | |
| 12 letters | ||
| stonyhearted | 12 | |
| heartofstone | 12 | |
| UNREMORSEFUL | 12 | |
| thick-witted | 12 | |
| hard-hearted | 12 | |
| unperceptive | 12 | |
| unresponsive | 12 | |
| 13 letters | ||
| unimpassioned | 13 | |
| unsympathetic | 13 | |
| Thick-skinned | 13 | |
| straight-face | 13 | |
| unsusceptible | 13 | |
| 14 letters | ||
| unaffectionate | 14 | |
| 15 letters | ||
| Self-absorption | 15 | |
| uncompassionate | 15 | |