| dour(adjective, close, hard, tough, severe) |
| granitic |
| hardhearted(adjective, hard, attitude, careless, cold) |
| resistant(adjective, hard, determined, resolute, unfeeling) |
| ruthless(adjective, mean, hard, tough, severe) |
| bigoted(adjective, determined, resolute, obstinate, uncompromising) |
| brassbound(adjective, resist, determined, resolute, persistent) |
| bull-headed(adjective, determined, resolute, obstinate, stubborn) |
| bullheaded(adjective, strong, hard, tough, deliberate) |
| business-minded |
| die-hard(adjective, resist, determined, resolute, persistent) |
| dogmatic(adjective, determined, fixed, hateful, rigid) |
| hanging tough(adjective, determined, resolute, stubborn, uncompromising) |
| impenitent(adjective, hard, tough, harsh, careless) |
| insensitive(adjective, mean, hard, cool, tough) |
| persevering(adjective, strong, tough, flat, firm) |
| pig-headed(adjective, determined, resolute, obstinate, stubborn) |
| self-willed(adjective, tough, firm, difficult, determined) |
| thick-skinned(adjective, hard, tough, severe, harsh) |
| unemotional(adjective, mean, hard, cool, tough) |