| indomitable(adjective, resolute, steadfast, unyielding) |
| inflexible(adjective, hard, rough, harsh, cruel) |
| malevolent(adjective, mean, evil, nasty, harsh) |
| sanguinary(adjective, hard, tough, harsh, violent) |
| steely(adjective, cold, cruel, resolute, unfeeling) |
| unconcerned(adjective, insensitive) |
| unemotional(adjective, hard, tough, severe, cold) |
| unscrupulous(adjective, honest, wicked, immoral) |
| virulent(adjective, evil, nasty, harsh, vicious) |
| adamant(adjective, mean, hard, rough, harsh) |
| aloof(adjective, insensitive) |
| anesthetized(adjective, hard, tough, severe, cold) |
| bold(adjective, resolute) |
| coarse(adjective, severe, rude, cruel, vicious) |
| coldhearted(adjective, mean, hard, severe, harsh) |
| detached(adjective, cruel, unfeeling, unsympathetic, pitiless) |
| determined(adjective, strong, harsh, cruel, fierce) |
| firm(adjective, resolute) |
| flinty(adjective, evil, nasty, harsh, cruel) |
| nasty(adjective, mean, hard, severe, sharp) |