Scoffs (at) (7)
'scoffs at' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for derides that I've seen before include "Ridicules" , "Mocks, scorns" , "Laughs at" .)
(Other definitions for sneezes that I've seen before include "Sternutations" , "Indications of hay fever?" , "Involuntary expulsions of air" , "Audible expirations through the nose" , "Sounds an 'atishoo'" .)