foolproof

adjective

fool·​proof ˈfül-ˌprüf How to pronounce foolproof (audio)
Synonyms of foolproofnext
: so simple, plain, or reliable as to leave no opportunity for error, misuse, or failure
a foolproof plan

Examples of foolproof in a Sentence

DNA fingerprinting gives police a virtually foolproof way to link a suspect to a crime scene.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
But nothing is foolproof, and there’s always a risk of bricking a device if something goes wrong. — ArsTechnica, 26 Oct. 2026 When in doubt, these sunglasses make a truly timeless, foolproof gift. — Genevieve Cepeda, InStyle, 21 Oct. 2026 But remember, says Reed, no prevention strategy is foolproof. — Andee Tagle, NPR, 15 Oct. 2026 Not without risk But even integration into the B-52 won’t be foolproof. — Christopher McFadden, Interesting Engineering, 11 Oct. 2026 See All Example Sentences for foolproof

Word History

First Known Use

1874, in the meaning defined above

Time Traveler
The first known use of foolproof was in 1874

Rhymes for foolproof

See All Rhymes for foolproof

Browse Nearby Words

foolometer
foolproof
foolscap
See all Nearby Words

Cite this Entry

“Foolproof.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/foolproof. Accessed 1 Nov. 2026.

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Kids Definition

foolproof

adjective
fool·​proof ˈfül-ˈprüf How to pronounce foolproof (audio)
: done, made, or planned so well that nothing can go wrong
foolproof directions

More from Merriam-Webster on foolproof

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