foolproof

[fool-proof]

adjective

involving no risk or harm, even when tampered with.
never-failing: a foolproof method.

Nearby words

  1. foolery,
  2. foolfish,
  3. foolhardy,
  4. foolish,
  5. foolishly,
  6. fools rush in where angels fear to tread,
  7. fools, feast of,
  8. foolscap,
  9. foosball,
  10. foot

Origin of foolproof

An Americanism dating back to 1900–05; fool1 + -proof

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for foolproof


British Dictionary definitions for foolproof

foolproof

adjective

proof against failure; infalliblea foolproof idea
(esp of machines) proof against human misuse, error, etc
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for foolproof

foolproof

adj.

also fool-proof, 1902, American English, "safe against the incompetence of a fool," from fool (n.) + proof.

Online Etymology Dictionary, © 2010 Douglas Harper