Contemptuous father going back inside shabby bar (8)
I believe the answer is:
derisive
'contemptuous' is the definition.
(I've seen this before)
'father going back inside shabby bar' is the wordplay.
'father' becomes 'sire' (synonyms).
'going back' says the letters should be written backwards.
'inside' indicates putting letters inside.
'shabby bar' becomes 'dive' (term for a sleazy bar).
'sire' written backwards gives 'eris'.
'eris' placed within 'dive' is 'DERISIVE'.
(Other definitions for derisive that I've seen before include "'Scornful, mocking (8)'" , "Expressing contempt" , "Contemptuous" , "Taunting" .)