Poor Dad is in contempt (7)
I believe the answer is:
disdain
'contempt' is the definition.
(I know that contempt can be written as disdain)
'poor dad is in' is the wordplay.
'poor' is an anagram indicator.
'dad'+'is'='dadis'
'dadis' anagrammed gives 'disda'.
'disda'+'in'='DISDAIN'
(Other definitions for disdain that I've seen before include "no respect" , "Haughtiness" , "Arrogance" , "Contempt for something unworthy of notice" , "Contumely" .)