fail-safe 1 of 2

adjective

ˈfāl-ˌsāf How to pronounce fail-safe (audio)
Definition of fail-safenext
as in reliable
not likely to fail flowers have been traditionally regarded as the fail-safe gift for Valentine's Day

Synonyms & Similar Words

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Antonyms & Near Antonyms

fail-safe

2 of 2

noun

as in precaution
a measure taken to preclude loss or injury there are so many fail-safes built into the system that a highly unlikely series of mistakes would have to be made before failure could occur

Synonyms & Similar Words

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Recent Examples of fail-safe
Adjective
The firewall is a fail-safe, as batteries are expected to operate well below 150 °C (302 °F). — New Atlas, 15 Apr. 2026 Adding even a blandly effective, third-pair option would be a playoff nice fail-safe. — Dom Luszczyszyn, New York Times, 6 Mar. 2026
Noun
Trump’s fail-safe failed to safe. — Emily Zemler, Rolling Stone, 9 June 2026 This fail-safe can help, so don’t ignore a warning. — Jason Fogelson, AJC.com, 29 May 2026 See All Example Sentences for fail-safe
Recent Examples of Synonyms for fail-safe
  1. reliable
  2. precaution
  3. surefire
  4. preventive
  5. infallible
Adjective
  • As governments and technology companies search for reliable, low-carbon power solutions, micro-modular reactors are emerging as one of several technologies being explored to support future electricity demand.
    — Prabhat Ranjan Mishra, Interesting Engineering, 16 July 2026
  • Industrial and real estate investment plunged in the first half of the year, indicating that such longtime pillars of the Chinese economy are becoming less reliable in offsetting slow consumption.
    — Stephanie Yang, CNN Money, 15 July 2026
Definition of reliable
Noun
  • Employees who work near the tower have been notified and are reportedly taking appropriate precautions.
    — Tessa Solomon, ARTnews.com, 15 July 2026
  • Understanding the gravity of a red flag warning and adhering to these precautions is pivotal in mitigating the risk of wildfires during these perilous conditions.
    — CA Weather Bot, Sacbee.com, 15 July 2026
Definition of precaution
Adjective
  • If Quaintance had been fully healthy for Kentucky, there’s a world where the 6-9 big man with a 7-5 wingspan might have been a surefire lottery selection.
    — Benjamin Royer, Oc Register, 20 June 2026
  • If this sounds familiar, that’s because this is a surefire case of de ja vu.
    — Blake Oestriecher, Forbes.com, 14 June 2026
Definition of surefire
Noun
  • In addition to making anti-vaccine comments, Kennedy also downplayed pediatric deaths related to measles and touted false cures and preventives, such as the use of vitamin A.
    — Mary Walrath-Holdridge, USA Today, 8 June 2026
  • Padlocks, sickles and other objects made of iron, a metal said to possess anti-demonic powers, were stashed in the grave as preventives.
    — Franz Lidz, New York Times, 5 Sep. 2023
Definition of preventive
Adjective
  • Not that the Coastal Commission has been infallible over the years.
    — Steve Lopez, Los Angeles Times, 11 July 2026
  • Both experts acknowledged that the tests are not infallible, can’t determine exactly when DNA was left on an item, and can't confirm the source of DNA with absolute certainty.
    — N'dea Yancey-Bragg, USA Today, 10 July 2026
Definition of infallible

Browse Nearby Words

fails
fail-safe
fail-safes
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Cite this Entry

“Fail-safe.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/fail-safe. Accessed 18 Jul. 2026.

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More from Merriam-Webster on fail-safe

Britannica.com: Encyclopedia article about fail-safe

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