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English definition of “alert”

alert

noun [C or U]     /əˈlɜːt/ US  /-ˈlɝːt/
C1 a warning to people to be prepared to deal with something dangerous : a bomb alert The army was put on ( full ) alert as the peace talks began to fail . The public were warned to be on the alert for (= watching carefully for) suspicious packages .Threats and warningsEmergency services in general
(Definition of alert noun from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)
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