WordWeb Online

1. Incapable of being transgressed or dishonoured
   "the person of the king is inviolable"; "an inviolable oath"
    
2. Immune to attack; incapable of being tampered with
   "fortifications that made the frontier inviolable"
   - impregnable, secure, strong, unassailable, unattackable
    
3. Must be kept sacred
   - inviolate, sacrosanct
    
4. Not capable of being violated or infringed
   "inviolable human rights"
   - absolute, infrangible

See also: inalienable, invulnerable, sacred, unalienable, unassailable, untouchable

Antonym: violable

Encyclopedia: Inviolable