Shy victim I disbelieved in part (5)
I believe the answer is:
timid
'shy' is the definition.
('timid' can be a synonym of 'shy')
'victim i disbelieved in part' is the wordplay.
'in part' indicates a hidden word.
'TIMID' is hidden within 'victim i disbelieved'.
(Other definitions for timid that I've seen before include "Inclined to avoid people" , "Bashful or fearful" , "Diffident, faint-hearted" , "Pusillanimous" , "Apprehensive and unassertive" .)