Husband's acted badly before divorce (6)
I believe the answer is:
detach
'divorce' is the definition.
(thesaurus)
'husband's acted badly before' is the wordplay.
'husband' becomes 'h'.
'badly' is an anagram indicator.
'before' is a charade indicator (letters next to each other).
'acted' is an anagram of 'detac'.
'h' after 'detac' is 'DETACH'.
(Other definitions for detach that I've seen before include "free" , "The reverse of 11 Down" , "Break off, come away" , "Separate from, remove part" , "Disengage, unfasten" .)