untouchable
adjective
1. beyond the reach of criticism or attack or impeachment
- for the first time criticism was directed at a hitherto untouchable target
Similar word(s): invulnerable
2. impossible to assail
Similar word(s): inviolable, unassailable
3. forbidden to the touch
- in most museums such articles are untouchable
Similar word(s): impermissible
4. (especially used in traditional Hindu belief of the lowest caste or castes) defiling
Similar word(s): impure, unclean
5. not capable of being obtained
- untouchable resources buried deep within the earth
Similar word(s): unavailable, inaccessible, unobtainable, unprocurable