idˈiocy /-ə-si/ or (rare) idˈiotcy noun

1. The state of being an idiot
2. Imbecility
3. Folly

idiotic /-otˈik/ or idiotˈical adjective

1. Relating to or like an idiot
2. Foolish

idiotˈically adverb

idˈiotish adjective

Idiotic

idˈiotism noun

1. The state of being an idiot (archaic)
2. An idiom (obsolete)

idiot board noun

A mechanical device used to prompt a speaker or performer on television, an autocue

idiot box noun (slang)

A television set

idiot card noun

A large card with words, etc, for the same purpose as an idiot board

idiot light noun (N American informal)

A light that comes on, eg on the dashboard of a car, when a fault is detected

idˈiot-proof adjective

(of a tool, device, machine, method of working, etc) so simple that even an idiot cannot make a mistake

idiot tape noun (computing)

A continuous unjustified tape for controlling a typesetting or filmsetting machine, which contains only paragraph break signals and needs processing to suit a particular page size