| undestroyable(adjective, moral, unable, lasting, principled) |
| changeless(adjective, stable, constant, enduring, lasting) |
| endless |
| indelible(adjective, stability, unable, lasting) |
| inextinguishable(adjective, moral, stability, unable, lasting) |
| invulnerable(adjective, strong, permanent, invulnerable, untouchable) |
| perdurable(adjective, strong, tough, stable, constant) |
| unending |
| incorruptible(adjective, strong, honest, moral, honorable) |
| unchanging(adjective, stable, constant, enduring, lasting) |
| hard(adjective, strong, firm, rigid, unyielding) |
| invincible(adjective, invulnerable) |
| timeless(adjective, lasting, permanent, everlasting, eternal) |
| adamant(adjective, firm, rigid, unyielding, steely) |
| ageless(adjective, lasting, permanent, everlasting, unending) |
| ceaseless |
| deathless(adjective, unable, lasting) |
| impregnable(adjective, unyielding, unassailable, untouchable, unconquerable) |
| long-lasting(adjective, tough, stable, sturdy, constant) |
| steely(adjective, firm, rigid, unyielding) |