Will meant to reform after the trial (9)
I believe the answer is:
testament
'will' is the definition.
(synonyms)
'meant to reform after the trial' is the wordplay.
'to reform' indicates anagramming the letters (letters in a new form).
'after' says to put letters next to each other.
'the trial' becomes 'test' ('test' can be a synonym of 'trial').
'meant' is an anagram of 'ament'.
'ament' put after 'test' is 'TESTAMENT'.
(Other definitions for testament that I've seen before include "with 1a [NEW] where is Mark?" , "it could be old or new" , "Either of the two main divisions of the Bible" , "(Person's) will" , "Scripture" .)