Scorn fiddle casual worker finally bought (8)
I believe the answer is:
contempt
'scorn' is the definition.
('contempt' can be a synonym of 'scorn')
'fiddle casual worker finally bought' is the wordplay.
'fiddle' becomes 'con'.
'casual worker' becomes 'temp' (I've seen this before).
'finally' suggests the final letters.
The last letter of 'bought' is 't'.
'con'+'temp'+'t'='CONTEMPT'
(Other definitions for contempt that I've seen before include "Feeling of disdain, sometimes of court" , "'Disdain, disrespect (8)'" , "Undisguised disrespect" , "Scorn; disgrace" , "Scornful feeling" .)