Setback for the other side (7)
I believe the answer is:
reverse
I believe this is a double definition.
'setback' is the first definition.
(I know that setback can be written as reverse)
'other side' is the second definition.
(thesaurus)
'for the' is the link.
(Other definitions for reverse that I've seen before include "Setback; go back" , "Do u-turn to reserve" , "Invert" , "Defeat - setback - other side" , "Tails (of a coin)" .)