adj

alert

uh-LURT

adj

Watchful and paying close attention; ready to notice or react quickly.

"Stay alert while driving at night."

"The guard dog remained alert to every sound outside."

noun

A warning or notification about something that needs attention.

"She got a weather alert on her phone about the incoming storm."

verb

To warn someone about something.

"A neighbor alerted the fire department to the smoke."

How to Use Alert

Learner’s notes

In plain EnglishBeing watchful and ready to react, or a warning message telling you something needs attention.

Common pairings

stay alert issue an alert on high alert security alert

more alert comparative, alerted past tense, alerts plural, alerts singular, most alert superlative

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Stay _____ while driving at night.

From French alerte, from the Italian phrase all'erta, "to the height" (i.e., watching from a tower or lookout).