to give something the green light 给予批准，开绿灯

在行车时绿灯表示通行。在其它情况下，如果说一个人给什么事或什么项目开了绿灯 to give something the green light 意思就是此人点头同意了，批准了这件事情或这个项目。

例句

Great news. The landlord has given us the green light to choose our own flatmate.

I read that the university has given the green light for the new library project.

请注意

另一个含义相似的表达是 to get the green light，意思是寻求批准，得到同意。

例句

I've got the green light to take some extra time off to finish my essay.

If you want to go on the field trip you'll have to get the green light from your parents.