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traffic light

American  

noun

  1. a set of electrically operated signal lights used to direct or control traffic at intersections.

traffic light British  

noun

  1. one of a set of coloured lights placed at crossroads, junctions, etc, to control the flow of traffic. A red light indicates that traffic must stop and a green light that it may go: usually an amber warning light is added between the red and the green

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of traffic light

First recorded in 1925–30

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

A previous dress rehearsal highlighted the need for a new traffic light at a specific location to alleviate gridlock when military convoys move across the country.

From The Wall Street Journal • Nov. 27, 2025

Indian home minister Amit Shah said the blast occurred around 7 p.m. in a Hyundai i20 car at a traffic light near the Red Fort.

From The Wall Street Journal • Nov. 10, 2025

The trust operated a traffic light system on patient files to indicate their level of need and the risk they posed to themselves or others.

From BBC • Nov. 9, 2025

Last month, police officers in San Bruno, CA, observed a self-driving Waymo make an illegal U-turn at a traffic light.

From Los Angeles Times • Oct. 21, 2025

I continued to stare at the traffic light, which glowed red.

From "The Poisonwood Bible" by Barbara Kingsolver

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.