Seclude, shut up (8)
I believe the answer is:
cloister
I believe this is a double definition.
'seclude' is the first definition.
(I've seen this in another clue)
'shut up' is the second definition.
(I've seen this in another clue)
(Other definitions for cloister that I've seen before include "Covered passage round cathedral courtyard" , "Monastic life" , "ambulatory" , "Covered walk round quadrangle" , "Covered walkway in religious institution" .)