idiot-proof

[id-ee-uh t-proof]

adjective

built, organized, written, etc., in such a way as to be usable by or understandable to any person of average intelligence or skill: an idiot-proof camera.

Origin of idiot-proof

probably earlier than 1975–80
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019