ˈ ̷ ̷| ̷ ̷ adjective
1. : so simple, plain, or strong as not to be liable to be misunderstood, damaged, or misused
foolproof tools
foolproof automatic washer
2. : guaranteed to operate without breakdown or failure under any conditions
foolproof elevator
foolproof rule of thumb
the system for reducing armaments must be foolproof — that is, proof against cheating by any nation — New York Herald Tribune
• fool·proof·ness noun -es