Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.
slang A warning light on the dashboard of an automobile meant to alert the driver to a potential problem, such as engine trouble, low fuel, overheating, etc. See? You ignore the idiot light, and the car ends up breaking down in the middle of nowhere.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
n. a light (instead of a meter) on a car’s dashboard that indicates the state of various things concerning the operation of the car. (Alludes to these lights’ elimination of the knowledge required to interpret a meter reading, making them suitable for idiots.) I don’t want idiot lights. I want meters!
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.