Definition of "fool-proof" []

• Proof even against the ignorant or meddlesome handling of fools; secure against accidents even in the hands of a stupid person: said of machinery.

The Century Dictionary (Public Domain)

• "The content was more along the lines of the inherent risks of STDs and the fact that abstinence is the only fool-proof method of avoiding them."
• "Broad of beam, heavily sparred, with high freeboard and bluff, Dutchy bow, the Uncle Toby was the slowest, tubbiest, safest, and most fool-proof schooner David Grief possessed."
• "Watch how Friedlander explains shadow fighting and hear some of his other fool-proof fighting tips in the interview below."