green light

/ˌgrin ˌˈlaɪt/

/grin laɪt/

Other forms: green lights

When someone gives you a green light, they're telling you it's okay to go ahead with your plan. Don't start painting the living room purple until you get the green light from your parents!

Green light has been used to mean "permission" since the 1930s. Just like a green traffic light tells cars or trains they're free to move forward, someone in authority giving you a green light is telling you to go ahead. This phrase is also used as a verb, especially in the film industry, where green lighting a project means promising to come up with enough money to make it happen, officially signaling to a filmmaker to proceed.

Definitions of green light

1. noun

   a signal to proceed
   synonyms: go-ahead

   type of:

   stoplight, traffic light, traffic signal

   a visual signal to control the flow of traffic at intersections
2. noun

   permission to proceed with a project or to take action
   type of:

   permission

   approval to do something