Have the opposite effect to that intended (8)
I believe the answer is:
backfire
(Other definitions for backfire that I've seen before include "Go wrong" , "Be self-defeating" , "Rebound on oneself" , "report" , "Boomerang" .)
I believe the answer is:
backfire
(Other definitions for backfire that I've seen before include "Go wrong" , "Be self-defeating" , "Rebound on oneself" , "report" , "Boomerang" .)