| steeled(noun, verb, adjective, set, strong) |
| stonyhearted(adjective, attitude) |
| thickened(verb, adjective, hard, firm, solid) |
| unbending(adjective, hard, firm, solid, careless) |
| uncontrite(adjective, hard, tough, harsh, cruel) |
| unforgiving(adjective, person, hard, tough, harsh) |
| accustomed(adjective, set, hard, usual, regular) |
| calcified(adjective, set, firm, solid, petrified) |
| chronic |
| dead |
| determined(fixed, stubborn, dogmatic) |
| emotionless(adjective, cool, blank, aloof, unemotional) |
| experienced(adjective, sophisticated, skilled, mature, seasoned) |
| firmed |
| flinty(adjective, rocky, pebbly) |
| incorrigible(adjective, bad, complete, rude, corrupt) |
| indurate(adjective, set, hard, firm, solid) |
| jelled(verb, adjective, hard, tough, firm) |
| opportunistic(sophisticated, experienced, mature, urbane, materialistic) |
| pachydermatous(noun, insensibility, physical insensibility) |