Inviolable

1. adjective

   immune to attack; incapable of being tampered with

   “an impregnable fortress”

   Similar: impregnable, secure, strong, unassailable, unattackable

2. adjective

   incapable of being transgressed or dishonored

   “the person of the king is inviolable”

3. adjective

   not capable of being violated or infringed

   “infrangible human rights”

   Similar: absolute, infrangible

4. adjective

   must be kept sacred

   Similar: inviolate, sacrosanct