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

---

Etymology

Origin of traffic light

First recorded in 1925–30

Example Sentences

Seven months ago, a self-driving Waymo made an illegal U-turn at a traffic light right in front of police officers in San Bruno.

From Los Angeles Times • May 1, 2026

"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

Under the new "traffic light system", Ofsted inspectors will use a five-point grading system, ranging from "urgent improvement" to "exceptional" to assess six areas of school performance.

From BBC • Nov. 11, 2025

At the last traffic light in the city, before she turned to go onto the great highway out of town, she stopped, waiting, and slid Dr. Montague’s letter out of her pocketbook.

From "The Haunting of Hill House" by Shirley Jackson

Related Words

• red light
• stoplight
• traffic control
• yellow light