Smiled derisively (7)
I believe the answer is:
sneered
'smiled derisively' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sneered that I've seen before include "Ridiculed" , "Mocked contemptuously" , "Smiled contemptuously" , "Showed contempt" , "Was contemptuous" .)