forestall - Dictionary definition and meaning for word forestall
Fore means before. Stall means to stop. Hence Forestall == Before Stop. i.e to stop something before it happens.
stall is to stop.. fore means before.. i.e fore + stall = taking precautions before itself, to prevent unwanted action..
Go FORward with putting the horse in the STALL to prevent him from getting out and causing trouble.
forestall = he has installed it previously; fore means previous.