1
- causing a piece of machinery to revert to a safe condition in the event of a breakdown or malfunction（机械）故障安全的; 有安全保障的：
a forklift truck with a fail-safe device.
装有安全保障装置的铲车。
1.1
- unlikely or unable to fail万全的, 不会失败的：
the computer that runs the place is supposed to be fail-safe.
管理这地方的电脑据说可以做到万无一失。
usu. in sing.
- a system or plan that comes into operation in the event of something going wrong or that is there to prevent such an occurrence安全保障系统（或计划）：
stewards positioned around the track as a fail-safe.
为确保安全在赛道周围的监管员。