Dad is wrong in showing contempt (7)
I believe the answer is:
disdain
'contempt' is the definition.
('disdain' can be a synonym of 'contempt')
'dad is wrong in' is the wordplay.
'wrong' is an anagram indicator.
'dad'+'is'='dadis'
'dadis' anagrammed gives 'disda'.
'disda'+'in'='DISDAIN'
'showing' acts as a link.
(Other definitions for disdain that I've seen before include "Haughtiness" , "Think unworthy, scorn" , "Look down on" , "Arrogance" , "'Contempt, condescension (7)'" .)