Definition of fail-safe in English:

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Pronunciation: /ˈfeɪlseɪf/


1Causing 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
More example sentences
  • Eyewear of the appropriate optical density is worn when using devices not equipped with fail-safe mechanisms.
  • The Tangara trains are equipped with a number of fail-safe devices, including one known as a deadman's brake.
  • With modern systems that relied more on fail-safe electronic units than on mechanical devices that could break down or malfunction at any time, flying had become a lot safer these days.
2Unlikely or unable to fail: there is no guaranteed fail-safe procedure
More example sentences
  • The good news is that having your teeth professionally whitened is not only affordable, which should last a lifetime with occasional top-ups - it is also a simple, noninvasive and virtually fail-safe procedure.
  • The campaign also has two back-up credit card transaction systems in place (one built in-house and one by a consultant) for high traffic periods and as a fail-safe procedure.
  • She wants not only clearer labelling but also a fail-safe device which would make it impossible for a drug to be wrongly administered.


[usually in singular]
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
More example sentences
  • The fail-safes on the program alert us when something gets neglected.
  • As an example, if you order a server from the company, when the order is submitted fail-safes within the system will alert us if a mistake has been made and won't allow the server to be configured incorrectly.
  • A small auxiliary throttle is used as a fail-safe should the system fail, to control fuel tank ventilation, and to improve cold starts.
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