a situation in which you are prepared for something dangerous to happen; a warning of this 紧急戒备状态；紧急警报 Following the bomb blast, local hospitals have been put on red alert. 炸弹爆炸之后，当地医院一直处于戒备状态。 🔊🔊 The water authority has issued a red alert until the cause of the pollution has been removed. 在污染原因消除之前，水务部门已发出红色警报。