Green light

The idiom to green light something has been in use for about a century. We will examine the meaning of the idiomatic phrase green light, where it came from, and some examples of its use in sentences.

To green light something means to give permission to proceed with an idea or task, to begin a project, to start something new. Green light may be used as a verb phrase or a noun. One may green light a project or one may give someone the green light to start a project. Green light is sometimes seen with a hyphen, as in green-light. Related phrases are green lights, green lit, green lighting, though these forms are most often seen with a hyphen. The expression green light is a clear reference to traffic signals–green means go, and red means stop. However, this color scheme was first used for signals in the railroad industry in the 1800s. The idiom to green light came into popular use in the 1930s when the proliferation of automobiles made it necessary to establish universal driving rules.

Examples

Griezmann Reportedly Gives FC Barcelona Green Light For Neymar Swoop As PSG Chase Renovation (Forbes)

Kevin Hart’s Night School gets the green light from NBC on a pilot order for TV series adaptation (The Daily Mail)

I wrote about East Village Green in October 2016 and am pleased to see that the park now has a green light to break ground in the summer of 2020, with the first phase ready by summer of 2022. (San Diego Downtown News)

Parkland Library gets green light to go out to bid on addition that would double space (The Morning Call)