| Interlingue | ile-000 |
| dur | |
| English | eng-000 | dour |
| English | eng-000 | hard |
| English | eng-000 | heartless |
| English | eng-000 | merciless |
| English | eng-000 | relentless |
| English | eng-000 | tough |
| Interlingue | ile-000 | cruel |
| Interlingue | ile-000 | desfacil |
| Interlingue | ile-000 | firm |
| Interlingue | ile-000 | fort |
| Interlingue | ile-000 | inexorabil |
| Interlingue | ile-000 | obstinaci |
| Interlingue | ile-000 | penosi |
| Interlingue | ile-000 | solid |
| Interlingue | ile-000 | ínexorabil |
| Interlingue | ile-000 | ínflexibil |
| Interlingue | ile-000 | ínhuman |
| Interlingue | ile-000 | ínsensibil |
| русский | rus-000 | твердый |