Model sneered at Cockney (4,5)
I believe the answer is:
east ender
'cockney' is the definition.
(I've seen this before)
'model sneered at' is the wordplay.
'model' indicates an anagram (the solver must model the letters into a new form).
'sneered'+'at'='sneeredat'
'sneeredat' with letters rearranged gives 'EAST-ENDER'.
(Other definitions for east ender that I've seen before include "Someone born within the sound of Bow Bells?" , "Londoner" , "Citizen" , "TV character" , "City dweller" .)