Backing Andre ensures some look of contempt (5)
I believe the answer is:
sneer
'look of contempt' is the definition.
(I've seen this in another clue)
'backing andre ensures some' is the wordplay.
'backing' says the letters should be written backwards.
'some' says the answer is hidden in the clue.
'reens' is hidden in the letters of 'andre ensures'.
'reens' backwards is 'SNEER'.
(Other definitions for sneer that I've seen before include "Show cynical contempt" , "Be derisive; Sheridan's Critic" , "Express cynical contempt" , "Smile contemptuously" , "Show contempt by contorting the face" .)