亮红灯
liàng​hóng​dēng

to show a red light

亮红灯 亮紅燈 liàng//hóng​dēng
to show a red light
To turn on a red signal light indicating that traffic must stop.
to give a warning
To reach a critical point or issue a warning signal regarding a dangerous situation, such as health or public safety.
to signal disapproval
To forbid something or show disapproval; to put a stop to an action.