| hard-line(adjective, strong, hard, tough, severe) |
| merciless(adjective, person, hard, rough, harsh) |
| pig-headed(adjective, determined, resolute, obstinate, stubborn) |
| single-minded(adjective, tough, firm, harsh, cruel) |
| strong-willed(adjective, determined, resolution, resolute, uncompromising) |
| unchanging(adjective, moderate, severe, firm, harsh) |
| bigoted(adjective, determined, resolute, rigid, obstinate) |
| business-minded |
| cruel(adjective, strong, hard, tough, severe) |
| dour(adjective, severe, severity) |
| hanging tough(expression, adjective, mean, hard, determined) |
| hard-boiled(adjective, person, mean, strong, hard) |
| indomitable(adjective, set, strong, hard, tough) |
| intolerant(adjective, set, severe, fixed, rigid) |
| pitiless(adjective, severe, harsh, cruel, determined) |
| precise(adjective, hard, severe, rough, difficult) |
| recalcitrant(adjective, tough, firm, unreasonable, fixed) |
| resistant(adjective, hard, firm, determined, resolute) |
| rock-ribbed(adjective, determined, resolute, uncompromising, unshakeable) |
| self-willed(adjective, tough, firm, determined, resolute) |