Dad's not out of trouble (4)
I believe the answer is:
pain
'trouble' is the definition.
(synonyms)
'dad's not out' is the wordplay.
'dad' becomes 'pa' (synonyms).
'not out' becomes 'in' ('in' is the opposite to 'out').
'pa'+'in'='PAIN'
'of' acts as a link.
(Other definitions for pain that I've seen before include "Tiresome figure" , "Agony" , "Sensation of hurt" , "Unpleasant sensation" , "Annoying person" .)