| tight(adjective, close, strong, hard, tough) |
| unadaptable(adjective, set, hard, stiff, rigid) |
| undeviating(adjective, strong, smooth, flat, harsh) |
| wilful(adjective, determined, resolute, uncompromising, unshakeable) |
| chilly(adjective, person, severe, feelings, response) |
| constant(adjective, strong, secure, moderate, flat) |
| contumacious(adjective, tough, firm, determined, unreasonable) |
| indurate(adjective, mean, hard, firm, determined) |
| ironclad(adjective, set, hard, severe, harsh) |
| persevering(adjective, strong, tough, flat, firm) |
| steady(adjective, strong, secure, moderate, flat) |
| sturdy(adjective, close, strong, hard, tough) |
| unflinching(adjective, strong, flat, firm, harsh) |
| unmoved(adjective, determined, fixed, stubborn) |
| willful(adjective, tough, firm, determined, resolute) |
| authoritarian(adjective, strong, hard, tough, severe) |
| bovine(adjective, determined, resolute, obstinate, uncompromising) |
| brass-bound(adjective, determined, resolute, obstinate, uncompromising) |
| demanding(adjective, hard, severe, rough, difficult) |
| exacting(adjective, severe, severity) |