Check scenery support (7)
I believe the answer is:
setback
'check' is the definition.
(I've seen this before)
'scenery support' is the wordplay.
'scenery' becomes 'set' (a stage set).
'support' becomes 'back' (to back is to support or endorse).
'set'+'back'='SETBACK'
(Other definitions for setback that I've seen before include "disappointment" , "Reverse" , "unfortunate event" , "Check" , "Hitch" .)