| hardened(noun, verb, adjective, set, strong) |
| callous(noun, adjective, hard, cruel, unfeeling) |
| enured |
| tough(noun, adjective, strong, hard, sound) |
| hard(adjective, careless, indifferent, cruel, apathetic) |
| insensitive(noun, adjective, hard, careless, indifferent) |
| seasoned(adjective, set, strong, hard, tough) |
| toughened(noun, adjective, hard, careless, indifferent) |
| trained(verb, adjective, familiar, skilled, experienced) |
| accustomed(adjective, set, hard, familiar, unfeeling) |
| case-hardened(noun, adjective, hard, careless, indifferent) |
| indurated(adjective, hard, careless, indifferent, cruel) |
| unfeeling(noun, adjective, hard, careless, indifferent) |
| acclimatized(adjective, strong, fit, familiar, healthy) |
| calloused |
| familiarized(verb, adjective) |
| habituated(adjective, set, hard, familiar, unfeeling) |
| hard-boiled(noun, adjective, hard, careless, indifferent) |
| impervious(noun, insensibility) |
| stony(adjective, hard, careless, indifferent, cruel) |