Show disdain (5)
I believe the answer is:
sneer
'show disdain' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sneer that I've seen before include "Contemptuous or mocking smile" , "Contemptuous look" , "Derisive remark" , "Deride, jeer" , "Contemptuous expression" .)