fail-safe

[ feyl-seyf ]

/ ˈfeɪlˌseɪf /

SEE MORE SYNONYMS FOR fail-safe ON THESAURUS.COM

adjective

Electronics. pertaining to or noting a mechanism built into a system, as in an early warning system or a nuclear reactor, for insuring safety should the system fail to operate properly.

equipped with a secondary system that insures continued operation even if the primary system fails.

(sometimes initial capital letter) of, relating to, or designating a system of coded military controls in which bombers dispatched to a prearranged point as part of a standard operating procedure cannot advance farther without direct orders from a designated authority and cannot have the nuclear warheads they carry armed until they have passed their prearranged point.

guaranteed to work; totally reliable: a fail-safe recipe for a cheese soufflé.

noun

(sometimes initial capital letter) the point beyond which the bombers cannot go without specific instruction; the fail-safe point.

something designed to work or function automatically to prevent breakdown of a mechanism, system, or the like.

verb (used with object), fail-safed, fail-saf·ing.

to make fail-safe.

Nearby words

fai, faial, faidherbe, faience, fail, fail-safe, fail-soft, failed, failed state, failing, faille

Origin of fail-safe

First recorded in 1945–50; apparently from verb phrase to fail safe(ly)

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for fail-safe

So as we lurch toward the next “fail-safe” milestone, there must be a way out for both sides.
CEO Solutions to the Shutdown|William L. McComb|October 14, 2013|DAILY BEAST
For example, at Three Mile Island, a fail-safe feature actually made the meltdown worse.
The Most Dangerous Substance in America May Be Fertilizer|Megan McArdle|April 19, 2013|DAILY BEAST
My Social Chef recommends the perfect, fail-safe roast chicken recipe.
The Perfect Roast Chicken|Petrit Husenaj|October 20, 2010|DAILY BEAST
Internally, the communications beam to Thule Base had been interrupted; and the fail-safe had not failed-safely.
Where I Wasn't Going|Walt Richmond

British Dictionary definitions for fail-safe

fail-safe

adjective

designed to return to a safe condition in the event of a failure or malfunction

(of a nuclear weapon) capable of being deactivated in the event of a failure or accident

unlikely to fail; foolproof

verb

(intr) to return to a safe condition in the event of a failure or malfunction

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012