Wife having bad self-control (4)
I believe the answer is:
will
'self-control' is the definition.
(I've seen this before)
'wife having bad' is the wordplay.
'wife' becomes 'w'.
'having' means one lot of letters go next to another.
'bad' becomes 'ill' ('ill' can be similar in meaning to 'bad').
'w'+'ill'='WILL'
(Other definitions for will that I've seen before include "Resolve - testament" , "A traditional question from the floor?" , "Intention, desire" , "Determination; 22 author" , "Intention; legal document" .)