| compact(adjective, set, hard, tough, solid) |
| thick-skinned(noun, adjective, calm, restrained, detached) |
| unapproachable(adjective, detached, unaffected, unyielding, unbending) |
| unfeeling(noun, adjective, bad, cold, indifferent) |
| unsusceptible(noun, adjective, resist, unresponsive, oblivious) |
| untouched(adjective, calm, restrained, subdued, impassive) |
| firm(adjective, set, strong, hard, tough) |
| unmoved(adjective, calm, indifferent, restrained, detached) |
| unyielding(adjective, hard, tough, solid, rigid) |
| waterproof(adjective, water, resistant) |
| cool(adjective, calm, indifferent, restrained, detached) |
| hard(adjective, set, tough, firm, solid) |
| impassive(adjective, calm, restrained, unconcerned, subdued) |
| insusceptible(adjective, resist, resistant) |
| inured(noun, insensibility) |
| inviolable(adjective, secure, solid, safe, dense) |
| pachydermatous(noun, adjective, insensibility) |
| sealed(adjective, fast, short, unyielding, unbending) |
| stony(adjective, unresponsive, oblivious, unmoved) |
| unattainable(adjective, inaccessible, impossible, impossibility) |