Stylish cross put back under cover (6)
I believe the answer is:
indoor
'under cover' is the definition.
(I've seen this before)
'stylish cross put back' is the wordplay.
'stylish' becomes 'in'.
'cross' becomes 'rood' (term for a crucifix).
'put back' is a reversal indicator.
'rood' back-to-front is 'door'.
'in'+'door'='INDOOR'
(Other definitions for indoor that I've seen before include "not alfresco" , "away from the other elements" , "under one roof?" , "For use in buildings" , "Within the house" .)