| insentient(adjective, dull, hard, careless, cold) |
| ruthless(adjective, mean, hard, harsh, cold) |
| unresponsive(adjective, hard, careless, indifferent, cruel) |
| unsympathetic(adjective, hard, careless, indifferent, cruel) |
| emotionless |
| impassible |
| mean(verb, adjective, hard, harsh, cold) |
| obtuse(adjective, hard, unfeeling, unsympathetic, hardened) |
| unemotional(adjective, hard, unfeeling, unsympathetic, impassive) |
| unimpressionable(adjective, hard, careless, indifferent, cruel) |
| unsusceptible(adjective, hard, careless, indifferent, cruel) |
| insusceptible |
| pitiless(adjective, hard, care, unfeeling, unsympathetic) |
| affectless |
| azoic(dull, cold, lifeless, nonliving, inorganic) |
| coldhearted(adjective, mean, hard, harsh, cold) |
| dead(adjective, dull, cold, lifeless, nonliving) |
| hard(adjective, careless, indifferent, cruel, apathetic) |
| hard-boiled(adjective, hard, careless, indifferent, cruel) |
| heavy |