| set in stone(expression, adjective, idiom, tough, firm) |
| single-hearted(adjective, keen, enthusiastic, devoted, loyal) |
| strong-willed(adjective, intense, deliberate, determined, serious) |
| unchangeable(adjective, set, hard, firm, solid) |
| uncooperative(adjective, persistent, obstinate, insistent, dogged) |
| unhesitating(adjective, firm, determined, serious, resolute) |
| unmanageable(tough, firm, persistent, obstinate, stubborn) |
| unremitting |
| unshakable(adjective, tough, firm, solid, determined) |
| unshaken(adjective, firm, solid, steady, stable) |
| wholehearted(adjective, keen, firm, sensible, solid) |
| absorbed in |
| adamantine(tough, firm, cruel, stiff, strict) |
| allegiant(adjective, firm, sensible, solid, intense) |
| anal-retentive(adjective, persistent, obstinate, insistent, dogged) |
| ardent(adjective, firm, sensible, solid, intense) |
| balky(tough, firm, unreasonable, grim, persistent) |
| be out for blood(intense, deliberate, determined, resolute, focused) |
| bent on(expression, adjective, serious, resolute, persistent) |
| biased(adjective, passionate, violent, fervent, inflexible) |