Definitions:

1. Extemely sacred, inviolable, or too important or respected to be interfered with or criticized. ADJECTIVE
   • The rituals performed in the temple are sacrosanct and strictly observed.
2. Regarded as most holy or untouchable, either in a religious, moral, or social sense. ADJECTIVE
   • The vow of a priest or nun is considered sacrosanct and inviolable.
3. Something that must be preserved or protected without question. ADJECTIVE
   • The sanctity of the Constitution is sacrosanct and must be fiercely defended.

Synonyms:

• hallowed
• inviolable
• sacred
• unassailable
• untouchable