| cussed(tough, firm, persistent, obstinate, stubborn) |
| dead set on(expression, adjective, idiom, firm, harsh) |
| diligent |
| earnest(adjective, sensible, determined, steady, serious) |
| engrossed |
| froward(adjective, persistent, obstinate, insistent, dogged) |
| hard(adjective, harsh, cruel, determined, fierce) |
| headstrong(adjective, tough, firm, unreasonable, grim) |
| hidebound(adjective, persistent, obstinate, stubborn, unbending) |
| immovable(adjective, firm, solid, intense, cruel) |
| implacable(adjective, tough, firm, harsh, cruel) |
| inalterable(adjective, inflexible) |
| insubordinate(tough, firm, persistent, obstinate, stubborn) |
| locked in(expression, adjective, tough, firm, cruel) |
| monomaniacal(adjective, passionate, violent, enthusiastic, fervent) |
| persisting |
| pigheaded(adjective, tough, firm, determined, resolute) |
| remorseless(adjective, tough, firm, harsh, cruel) |
| sedulous |
| serious(adjective, firm, sensible, steady, resolute) |