| Clue | Source | Date |
|---|---|---|
| Hard, stony | The Sun Mini | 13 Jul 2025 |
| Unyielding | Wall Street Journal | 15 Sep 2023 |
| As unyielding as rock | Universal | 16 Nov 2020 |
| Hard and unyielding | New York Times | 29 Mar 2015 |
| Hard and unyielding | ||
| Stern and unyielding | ||
| Unfeeling | ||
| Unyielding | ||
| Unyielding | ||
| Stony toward tender feelings | ||
| Unyielding | ||
| Unyielding | ||
| Obdurate | ||
| Hard. |