Definition of "foolproof" []

  • Designed so as to be impervious to human incompetence, error, or misuse: a foolproof detonator; a foolproof safety lock. (adjective)
  • Effective; infallible: a foolproof scheme. (adjective)
  • Proof against failure; infallible (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

  • (esp of machines) proof against human misuse, error, etc (adjective) (c) HarperCollins Publishers Ltd 2016

Use "foolproof" in a sentence
  • "“A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.”"
  • "Curse that Aimee and her so-called foolproof formula for success: “Wear your hair down and the highest heels you have, then watch the tips roll in.”"
  • "The little formulas that the smart boys who design these so-called foolproof systems build in so they can sneak a gander whenever they feel like it."