| merciless(adjective, person, mean, hard, tough) |
| numb(noun, verb, adjective, dull, hard) |
| obdurate(adjective, person, mean, hard, cool) |
| harsh(adjective, mean, hard, cool, tough) |
| inhuman(adjective, mean, bad, hard, tough) |
| thick-skinned(noun, adjective, calm, mean, hard) |
| uncompassionate(adjective, person, mean, hard, cool) |
| emotionless(adjective, bad, cool, cold, indifferent) |
| pitiless(adjective, mean, hard, tough, severe) |
| unresponsive(adjective, calm, person, quiet, mean) |
| brutal(adjective, mean, hard, tough, severe) |
| indurate(verb, adjective, dull, close, set) |
| unkind(adjective, mean, bad, hard, cool) |
| hardhearted(adjective, mean, hard, severe, attitude) |
| impassive(adjective, calm, hard, cool, cold) |
| unconcerned(adjective, calm, mean, hard, cool) |
| impervious(noun, adjective, calm, bad, cold) |
| inured(noun, adjective, hard, cruel, unfeeling) |
| remorseless(adjective, mean, harsh, cold, cruel) |
| cold-hearted(adjective, hard, tough, severe, attitude) |