fail-safe
Americanadjective
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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.
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equipped with a secondary system that insures continued operation even if the primary system fails.
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(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.
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guaranteed to work; totally reliable.
a fail-safe recipe for a cheese soufflé.
noun
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(sometimes initial capital letter) the point beyond which the bombers cannot go without specific instruction; the fail-safe point.
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something designed to work or function automatically to prevent breakdown of a mechanism, system, or the like.
verb (used with object)
adjective
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designed to return to a safe condition in the event of a failure or malfunction
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(of a nuclear weapon) capable of being deactivated in the event of a failure or accident
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unlikely to fail; foolproof
verb
Etymology
Origin of fail-safe
First recorded in 1945–50; apparently from verb phrase to fail safe(ly)
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
As a key oil producer, Saudi Arabia is relied upon to surge output and stabilize markets during crises, but any physical degradation of its export capacity neuters this critical fail-safe.
“Ella changed ink and words into magic. She turned that into something. Remember what Ollie said? There’s a fail-safe. We already have the door. It’s in the words from the missing pages.”
From Literature
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The boats had rejected their inputs and automatically idled as a fail-safe, making them “dead” in the water.
“Only the person who activated the STM can use it again. My mom has fail-safes against everything.”
From Literature
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Even if you plan to be fully engaged with managing money into retirement, a financial adviser could be a fail-safe if you can no longer make sound decisions.
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.