Showing unwillingness, enact cruel change (10)
I believe the answer is:
reluctance
'showing unwillingness' is the definition.
'enact cruel change' is the wordplay.
'change' is an anagram indicator.
'enact'+'cruel'='enactcruel'
'enactcruel' with letters rearranged gives 'RELUCTANCE'.
(Other definitions for reluctance that I've seen before include "Hesitation" , "averse reaction" , "Unwillingness (to do something)" , "Wariness" .)