invulnerable Synonyms

protected from danger unassailable bulletproof airtight armour-plated unsusceptible unyielding unpenetrable undestroyable unconquerable tight strong sound solid shielded case-hardened untouchable unsubduable safeguarded well defended closed to unpierceable uninjectable unhazardous unstoppable risk-free impregnably low-risk unhackable undefeatable unbeatable unattackable sheltered shellproof indomitable indestructible impregnable impervious impermeable impenetrable impassable immune guarded firm defensible defendable defended armor-plated inexpugnable inextinguishable