Contract to restore a convent (8)
I believe the answer is:
covenant
'contract' is the definition.
(covenanting is a kind of contracting)
'restore a convent' is the wordplay.
'restore' indicates an anagram.
'a'+'convent'='aconvent'
'aconvent' is an anagram of 'COVENANT'.
'to' acts as a link.
(Other definitions for covenant that I've seen before include "Signed agreement between two or more to do something" , "Formal agreement in a convent" , "Contract made in a convent" , "Formal agreement between two or more parties" , "Promise" .)