Criminal lout upset a wife (6)
I believe the answer is:
outlaw
'criminal' is the definition.
('outlaw' can be a synonym of 'criminal')
'lout upset a wife' is the wordplay.
'upset' indicates anagramming the letters.
'wife' becomes 'w'.
'lout' with letters rearranged gives 'outl'.
'outl'+'a'+'w'='OUTLAW'
(Other definitions for outlaw that I've seen before include "Josey Wales was one" , "Nonconformist" , "He broke the rules in the old West" , "Wanted criminal" , "Irish Tory" .)