Disdain shown by prisoner over bait (8)
I believe the answer is:
contempt
'disdain' is the definition.
('contempt' can be a synonym of 'disdain')
'prisoner over bait' is the wordplay.
'prisoner' becomes 'con' (abbreviation for 'convict').
'over' is a charade indicator (letters next to each other).
'bait' becomes 'tempt' (I've seen this before**).
'con'+'tempt'='CONTEMPT'
'shown by' is the link.
(Other definitions for contempt that I've seen before include "Feeling of disdain, perhaps of court" , "Undisguised disrespect" , "Disobedience to the rules of a court of law" , "Scornful feeling" , "The feeling of despising someone" .)