Rioting is over -- caught in a new hostility (8)
I believe the answer is:
aversion
'hostility' is the definition.
(thesaurus)
'rioting is over caught in a new' is the wordplay.
'rioting' is an anagram indicator (I've seen this in other clues).
'caught in' is an insertion indicator.
'a new' becomes 'an' (I've seen this in other clues**).
'is'+'over'='isover'
'isover' with letters rearranged gives 'versio'.
'versio' placed inside 'an' is 'AVERSION'.
(Other definitions for aversion that I've seen before include "A strong dislike for something - turn away from it" , "Strong disinclination" , "serious dislike" , "A strong dislike or antipathy" , "phobia" .)