1. (Judaism) sanctuary comprised of the innermost chamber of the Tabernacle in the temple of Solomon where the Ark of the Covenant was kept
   "Only the high priest could enter the sanctum sanctorum on Yom Kippur";
   - holy of holies
    
2. A place of inviolable privacy
   "he withdrew to his sanctum sanctorum, where the children could never go";
   - sanctum

Derived forms: sanctum sanctorums

Type of: retreat, sanctuary

Part of: Tabernacle

Encyclopedia: Sanctum sanctorum