| hardened(adjective, determined, fixed, resolute, stubborn) |
| harsh(adjective, mean, strong, hard, tough) |
| heartless(adjective, mean, cool, detached, blank) |
| icy(adjective, cool, detached, blank, sober) |
| inactive(still, passive, motionless, stationary, quiescence) |
| inalterable(adjective, inflexible) |
| incompliant(adjective, difficult, determined, resolute, stubborn) |
| inconvincible(adjective, determined, resolute, uncompromising, unshakeable) |
| indefatigable |
| indomitable(adjective, strong, hard, tough, difficult) |
| ironclad(adjective, set, hard, cruel, usual) |
| locked in(expression, adjective, secure, wild, determined) |
| nonemotional(adjective, cool, flat, detached, blank) |
| parochial |
| restful |
| self-opinionated(adjective, determined, resolute, uncompromising, unshakeable) |
| serene(adjective, calm, cool, firm, solid) |
| single-minded(adjective, firm, solid, intense, cruel) |
| stagnant(adjective, still, fixed, passive, motionless) |
| sturdy(adjective, strong, hard, tough, firm) |