1

fail-safe

adjective \ ˈfāl-ˌsāf \

Definition of fail-safe

1 : incorporating some feature for automatically counteracting the effect of an anticipated possible source of failure
2 : being or relating to a safeguard that prevents continuing on a bombing mission according to a preconceived plan
3 : having no chance of failure : infallibly problem-free
  • the little black dress … has consistently been the fail-safe solution for night
  • Vogue

First Known Use of fail-safe

1946

in the meaning defined at sense 1

See Words from the same year
NEW! Time Traveler

fail-safe Synonyms


2

fail-safe

noun

Definition of fail-safe

: a device or measure that makes something fail-safe

First Known Use of fail-safe

1975

in the meaning defined above

See Words from the same year
NEW! Time Traveler

fail-safe Synonyms


FAIL-SAFE Defined for English Language Learners

fail-safe

Definition of fail-safe for English Language Learners

  • : certain not to fail



Seen and Heard

What made you want to look up fail-safe? Please tell us where you read or heard it (including the quote, if possible).

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

resembling the blue of the sky

Get Word of the Day daily email!

Test Your Vocabulary

Difficult Spelling Words Quiz

  • alphabet-pasta-spelling-help
  • Which is the correct spelling?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

TAKE THE QUIZ
Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!