| mulish(adjective, mean, hard, harsh, inflexible) |
| not responsive(expression, adjective, detached, impassive, unresponsive) |
| obstinate(adjective, mean, hard, harsh, inflexible) |
| obtuse(adjective, hard, unfeeling, unsympathetic, hardened) |
| oppressive |
| perverse(adjective, mean, hard, tough, harsh) |
| prepared(adjective, hard, unfeeling, unsympathetic, hardened) |
| quiet(adjective, detached, impassive, unresponsive, laid-back) |
| repellent(adjective, mean, hard, cool, unpleasant) |
| reserved(adjective, detached, impassive, unresponsive, laid-back) |
| resistant(adjective, hard, unfeeling, unsympathetic, hardened) |
| rigid(adjective, mean, hard, harsh, inflexible) |
| rocky(adjective, pebbly, flinty) |
| seasoned(adjective, hard, unfeeling, unsympathetic, hardened) |
| sensationless(adjective, hard, tough, severe, cold) |
| senseless(adjective, hard, tough, severe, cold) |
| set in stone(expression, adjective, idiom, mean, hard) |
| sinister(adjective, evil, negative) |
| soulless(adjective, hard, careless, indifferent, cruel) |
| spiritless(adjective, hard, careless, indifferent, cruel) |