Resist work – be a model! (6)
I believe the answer is:
oppose
'resist' is the definition.
(I know this)
'work be a model' is the wordplay.
'work' becomes 'op' (abbreviation for opus).
'be a model' becomes 'pose' (I've seen this in another clue).
'op'+'pose'='OPPOSE'
(Other definitions for oppose that I've seen before include "Resist, contend with" , "face" , "Resist, be hostile to" , "'Refute, stand against (6)'" , "Refute - confront" .)