foolproof

adjective

fool·​proof ˈfül-ˌprüf 

: 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

Beige Much like gray, beige is often seen as a foolproof choice. —Marisa Suzanne Martin, The Spruce, 7 Mar. 2026

To avoid disaster, the two hatch a foolproof plan. —Randy Myers, Mercury News, 4 Mar. 2026

To round out the dish, add rotisserie chicken, peas, and herbs for a foolproof one-pot meal that tastes like you’re dining in a restaurant. —Marianne Williams, Southern Living, 21 Feb. 2026

Protective barriers like rug pads can help with distributing the weight from a heavy piece of furniture, but these aren't foolproof, Cox says. —Caroline Lubinsky, Martha Stewart, 19 Feb. 2026

Word History

First Known Use

1874, in the meaning defined above

Rhymes for foolproof

• aloof
• behoof
• disproof
• flameproof
• greaseproof
• leakproof
• reproof
• soundproof
• bulletproof
• fireproof
• waterproof
• weatherproof

Kids Definition

foolproof

adjective

fool·​proof ˈfül-ˈprüf 

: done, made, or planned so well that nothing can go wrong

foolproof directions