green light, the

Idioms

Permission to go ahead, as in The chief gave us the green light for starting this project. This term originated in the late 1800s for the signal used by railroads to indicate that a train could proceed. It was transferred to more general use in the first half of the 1900s.

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.

Elon Musk is still waiting for Chinese officials to green light the car company’s Full Self-Driving technology.

From Barron's • May 14, 2026

The ruling last month that had appeared to green light the latest planned auction was handed down by the High Court in Pretoria, which will now review whether to allow an appeal of its decision.

From New York Times • Jan. 18, 2024

But if one or more of the candidates gets the green light, the mRNA revolution could reach many more people.

From Science Magazine • Apr. 4, 2022

On 3 February, Cincinnati City Council voted to green light the development.

From BBC • Feb. 21, 2021

It was a pale green light, the kind you see from one of those snap-activated glow sticks; it lit the stairwell, and then everything was suddenly dark again.

From "Winger" by Andrew Smith

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