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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 broad traffic light assessment of the public finances would make governments' multiple objectives – and the associated trade-offs faced – much more transparent and explicit," she said.

From BBC • Feb. 18, 2026

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

Some call them a "traffic light system"; critics have likened them to Nando's spice cards.

From BBC • Nov. 11, 2025

And when you are coming up to a traffic light, you want to keep some momentum, if you can.

From The Wall Street Journal • Oct. 26, 2025

We pull to a stop at the traffic light, and the air changes.

From "Fast Pitch" by Nic Stone

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.