from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Slang Made or designed to be used or operated with very little risk of breakage or failure: "These point-and-shoot cameras are almost idiot-proof” ( Donald H. Dunn).
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Incapable of being misused even by the most stupid or careless of users.
idiot + -proof (Wiktionary)