Scornful (6)
'scornful' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for derisive that I've seen before include "'Scornful, mocking (8)'" , "Expressing contempt" , "Taunting" , "Contemptuous" .)
(Other definitions for scathing that I've seen before include "Severely critical" , "Scornfully critical" , "Acid" , "Caustic" , "Harshly critical" .)
'scornful' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for sniffy that I've seen before include "Supercilious; snobby" , "Disdainful" , "Scornful, contemptuous" .)