| relentless(adjective, strong, tough, cold, determined) |
| tough(adjective, hard, rough, firm, difficult) |
| balky(tough, firm, cross, negative, hostile) |
| bulldogged(adjective, tenacious) |
| deliberate(adjective, determined, resolute, intentional) |
| fanatical(adjective, fervent, rash, zealous, volatile) |
| fixed(adjective, tough, firm, determined, unreasonable) |
| fractious(adjective, violent, wild, deliberate, determined) |
| grim(adjective, determined, resolute, uncompromising, unshakeable) |
| heady(adjective, determined, fixed, stubborn, obstinacy) |
| implacable(adjective, determined, resolute, uncompromising, unshakeable) |
| indomitable(adjective, tough, violent, wild, awkward) |
| naughty(adjective, bad, misbehaved) |
| precipitate(adjective, careless, anxious, bold, worried) |
| rash(adjective, mean, violent, careless, wild) |
| resolved(adjective, deliberate, determined, fixed, resolute) |
| restive(determined, negative, hostile, fixed, different) |
| stony(adjective, tenacious) |
| strong-minded(adjective, determined, fixed, resolute, impulsive) |
| wrongheaded(negative, hostile, different, adverse, conflicting) |