Show contempt for a roasting rod (4)
I believe the answer is:
spit
I believe this clue is a double definition.
'show contempt' is the first definition.
(I've seen this before)
'roasting rod' is the second definition.
(I've seen this before)
'for a' is the link.
(Other definitions for spit that I've seen before include "Rotating cooker" , "Cooker - likeness" , "Narrow strip of land almost surrounded by water" , "hawk" , "issue with some violence" .)