green light

名词 green light:

1. a signal to proceed
   同义词：go-ahead
2. permission to proceed with a project or to take action

1. At night, ships at sea carry a red light on the port side and a green light on the starboard.
   夜晚，在港口左边一边的海船上有红灯，在右舷的船上有绿灯。
2. Before the traffic signal turns to green light don't cross the street.
   在交通信号轮换到绿灯以前不要穿过马路。
3. The driver waited for the green light, his engine racing.
   那司机等候绿灯放行，让发动机空转著。