Won’t change borough (4)
I believe the answer is:
town
'borough' is the definition.
(thesaurus)
'won't change' is the wordplay.
'change' is an anagram indicator.
'wont' is an anagram of 'TOWN'.
(Other definitions for town that I've seen before include "See 9" , "London" , "Built up area" , "Milton Keynes, say, with 1a [NEW]" , "Borough" .)