A holy place can and must reform (7)
I believe the answer is:
sanctum
'a holy place' is the definition.
(synonyms)
'can and must reform' is the wordplay.
'and' says to put letters next to each other.
'reform' indicates an anagram (letters in a new form).
'can' after 'must' is 'mustcan'.
'mustcan' anagrammed gives 'SANCTUM'.
(Other definitions for sanctum that I've seen before include "somewhere private" , "Holy area" , "Room safe from disturbance" , "Holy place, often inner" , "Sacred or safe place" .)