Look of disdain (5)
I believe the answer is:
sneer
'look of 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 "Taunt" , "Show contempt with scornful expression or words" , "Express cynical contempt" , "Contemptuous gesture" , "Curl one's lip" .)