Nothing interrupts reviled, dishevelled criminal (8)
I believe the answer is:
evildoer
'criminal' is the definition.
(thesaurus)
'nothing interrupts reviled dishevelled' is the wordplay.
'nothing' becomes 'O' (looks like zero - 0).
'interrupts' means one lot of letters goes inside another.
'dishevelled' is an anagram indicator.
'reviled' with letters rearranged gives 'evilder'.
'o' going inside 'evilder' is 'EVILDOER'.
(Other definitions for evildoer that I've seen before include "One committing wicked deeds" , "miscreant" , "criminal!" , "sinner" , "Rode live over morally bad person" .)