Villain's expression (5)
I believe the answer is:
sneer
'villain's expression' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for sneer that I've seen before include "Be derisive; Sheridan's Critic" , "Scoff, scorn" , "Speak contemptuously" , "Speak scornfully" , "Contemptuous expression" .)