alert - definition in the American English Dictionary - Cambridge Dictionaries Online

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English definition of “alert”

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adjective  us   /əˈlɜrt/
quick to see, understand, and act in a particular situation: When you’re driving, you must stay alert. We had to be alert to any danger signs in the economy.


noun [C/U]  us   /əˈlɜrt/
a warning to people to get ready to deal with something dangerous: [U] The police were on the alert for (= watching carefully for) any sign of trouble.
verb [T]  us   /əˈlɜrt/
The auto company mailed letters to owners of that model car, alerting them of safety risks.
(Definition of alert from the Cambridge Academic Content Dictionary © Cambridge University Press)
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