Sacred recess (4)
I believe the answer is:
apse
'sacred recess' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for apse that I've seen before include "Peas (anag) - found in church" , "Where the altar is usually found in a church" , "room for an altar" , "Where you could find a magistrate's chair" , "Church recess with domed or arched roof" .)