Contemptuous (8)
I believe the answer is:
scornful
'contemptuous' is the definition.
(I know that contemptuous can be written as scornful)
This is all the clue.
(Other definitions for scornful that I've seen before include "Mocking" , "Openly contemptuous" , "Contemptuous or derisive" , "Expressing extreme contempt" , "Dismissive, contemptuous" .)