fail-safe
adjective
[ ˈfeɪlseɪf ]
• causing a piece of machinery to revert to a safe condition in the event of a breakdown or malfunction.
• "a forklift truck with a fail-safe device"
• unlikely or unable to fail.
• "there is no guaranteed fail-safe procedure"
fail-safe
noun
• a system or plan that comes into operation in the event of something going wrong or that is in place to prevent such an occurrence.
• "stewards positioned around the track as a fail-safe"
