from The American Heritage® Dictionary of the English Language, 4th Edition

  • adj. Capable of compensating automatically and safely for a failure, as of a mechanism or power source.
  • adj. Acting to discontinue a military attack on the occurrence of any of various predetermined conditions.
  • adj. Guaranteed not to fail: "There is no fail-safe mechanism guaranteed either to contain or to restore presidential authority” ( Arthur M. Schlesinger, Jr.)
  • n. A fail-safe mechanism.
  • intransitive v. To compensate automatically for failure.
  • transitive v. To render fail-safe: fail-safed the computer against power outages.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • adj. That doesn't cause undue damage, in the event of failure.
  • n. A fail-safe device or mechanism.
  • v. To compensate automatically, in the event of a failure.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adj. eliminating danger by compensating automatically for a failure or malfunction
  • n. a mechanism capable of returning to a safe state in case there is a failure or malfunction
  • adj. guaranteed not to fail


Sorry, no etymologies found.


  • But it is somewhat sobering to see all these so-called 'fail-safe' mechanisms failing.'' Top Stories

  • Cameron was the maker of the blowout preventer, the so-called fail-safe device that neglected to automatically shut down the well.

    Reuters: Top News

  • Cameron made the blowout preventer for the well, a so-called fail-safe device that failed to automatically shut down the well.

  • But maintaining a remote fail-safe system is trickier when dealing with employees' devices, which store their own apps, photos and other information.


  • This is the problem when designing fail-safe systems -- they fail in the most unexpected ways.

    Donald Kaul: The Dangers of Nuclear 'Ice-Nine'

  • The fail-safe device, the last line of defense against a disaster, wasn't designed to handle a real-world blowout, according to investigators, who called for further study of the devices.

    Device's Design Flaw Let Oil Spill Freely

  • Once it reached the rig, the gas ignited, setting off a massive explosion that killed the 11 workers and knocked out the rig's power, leaving survivors with no way to trigger the final fail-safe on the blowout preventer, the pipe-cutting shears known as blind-shear rams, while they were still aboard the rig.

    Device's Design Flaw Let Oil Spill Freely

  • I sat down with the South African native - who has lived in New York since the late 1970s - to discuss his inspirations for the event launch, his upcoming projects, and his fail-safe secrets to entertaining.

    Melissa Berkelhammer: Behind the Scenes With Geoffrey Bradfield

  • Modern rail systems are supposed to have fail-safe measures to prevent such occurrences.

    China Fires Officials After Crash Kills 35

  • A sumptuous boar blow-out closes Mr. Greene's account, as if, all other approaches falling short, one fail-safe way to comprehend this beast is to eat him.

    Stalking the Beast


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