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red light (traffic)
red light; signal to stop; sign of danger
車は赤信号で止まった。
The car stopped at the red light.
自転車が赤信号を無視し、罰金を取られた。
The cyclist ran the red light and was fined.
交差点に近づくと、信号が赤信号に変わった。
As I approached the intersection, the light turned red.