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Definitions

fail-safe

[feyl-seyf] / ˈfeɪlˌseɪf /
ADJECTIVE
guaranteed not to fail
Synonyms
STRONG
sound
WEAK
covered foolproof protected reliable reliant safeguarded secure sure

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.

Those recorded cues act as a fail-safe against technical malfunctions during the broadcast, though the orchestra aims to play everything live.

From Los Angeles Times • Mar. 13, 2026

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.

From The Wall Street Journal • Nov. 5, 2025

There’s no 100% safe way to lift 500 pounds, just like there is no fail-safe way of throwing 100 mph.

From Los Angeles Times • Jul. 20, 2025

Margery had extremely strong principles about fail-safe commands.

From Slate • Jan. 27, 2024

Whenever those thoughts spring up, my sister is the fail-safe.

From "Challenger Deep" by Neal Shusterman