black flag
noun
1
- historical a pirate's ensign, typically thought to feature a white skull and crossbones on a black background〈史〉海盗旗（通常绘有白色骷髅和交叉的大腿骨, 黑底）。
2
- historical a black flag hoisted outside a prison to announce an execution〈史〉（宣布执行死刑时在监狱外悬挂的）黑旗。
3
- Motor Racing a black flag used to signal to a driver that he must stop at the pits as a punishment for a misdemeanour【赛车】黑旗（赛车时的信号旗, 用于表示赛车手因犯规遭处罚, 必须在车道检修站停车）。