Put away, he hates to reform (7)
I believe the answer is:
sheathe
'put away' is the definition.
'he hates to reform' is the wordplay.
'to reform' is an anagram indicator.
'he'+'hates'='hehates'
'hehates' is an anagram of 'SHEATHE'.
(Other definitions for sheathe that I've seen before include "Cover in case" , "Put (a sword) into case" , "Protective cover, for sword say" , "Put into scabbard" , "Put away (a sword)" .)