Synonyms of fail-safe

fail-safe 1 of 2

adjective

ˈfāl-ˌsāf 

as in reliable

not likely to fail

flowers have been traditionally regarded as the fail-safe gift for Valentine's Day

Synonyms & Similar Words

• reliable
• surefire
• infallible
• sure
• unfailing
• dependable
• certain
• can't-miss
• deadly
• unerring

Antonyms & Near Antonyms

• uncertain
• doubtful
• questionable
• fallible

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

• precaution
• preventive
• safeguard
• protection
• caution
• shield
• palladium
• wall
• screen
• armor
• ward
• guard
• cover

Example Sentences

Recent Examples of fail-safe

Adjective

Adding even a blandly effective, third-pair option would be a playoff nice fail-safe. — Dom Luszczyszyn, New York Times, 6 Mar. 2026

This suggests gaps in contingency planning and basic fail-safe design. — Missy Cummings, IEEE Spectrum, 2 Mar. 2026

Noun

It is backed by a 10-minute thermal buffer tank and a 72-hour emergency water reserve to ensure continuous, fail-safe climate control. — Mrigakshi Dixit, Interesting Engineering, 29 June 2026

Not to mention, the flattering waist tie and subtle side slit elevate your look ever so slightly without overwhelming, a fail-safe formula for chic European dressing. — Julia Morlino, Travel + Leisure, 23 June 2026