noun
sanctum
SANGK-tum/ˈsæŋktəm/
A protected place set apart from ordinary access.
Her upstairs study is a sanctum where she works undisturbed.

Etymology
Latin sanctum meant a holy place. The idea of a space set apart as sacred later extended to a person's private room or retreat.
In context
the treasury is The Keeper of the secrets budget plans are highly Market sensitive and only a few mandarins are allowed access to the inner sanctum
More examples
- Only the priests may enter the temple's inner sanctum.
- He treats his workshop as a sanctum, closed to visitors.
- She escapes to her garden sanctum after a busy day.
Forms
sanctum · sanctums · sancta