Fail-safe synonyms | adjectives

Synonyms for Fail-safe as an Adjective

• sure

  guaranteed not to fail
• reliable

  guaranteed not to fail
• foolproof

  guaranteed not to fail, thrive
• secure

  guaranteed not to fail
• safe
• dependable
• unfailing
• certain
• sound

  guaranteed not to fail
• tested
• surefire
• protected
• good
• infallible
• tried
• guaranteed
• unerring
• confident
• safeguarded
• trustworthy
• true
• proven
• tried and tested
• established
• excellent
• flawless
• sure-fire
• unassailable
• perfect
• faultless
• goofproof
• idiot-proof
• never-failing
• covered
• reliant
• safe and sound
• uninjured
• assured
• can't-miss
• trusted
• tried and true
• loyal
• faithful
• staunch
• steadfast
• constant
• unswerving
• unwavering
• well-established
• long-established