alert

Everyday

1. Watching and listening carefully, awake and ready to notice danger or act quickly. tree →
2. A warning signal or message about danger or something important (a weather alert, a phone alert). tree →
3. To warn someone or tell them about something so they can act. tree →
4. On the alert / on high alert: ready and watching for danger. tree →

In the lessons

In safety lessons «be alert» means keep your eyes and ears open: crossing roads, near water, in crowds. Phones and computers send alerts (notifications); authorities send weather alerts for storms, floods, fires. Animals are alert to predators. Phrases: stay alert, on the alert, high alert, alert someone to something, flood alert, amber alert.

Examples

• Stay alert when you cross the road. tree →
• The meerkat stood up, alert for eagles. tree →
• My phone gave an alert when the message arrived. tree →
• The town got a flood alert after the heavy rain. tree →
• A neighbour smelled smoke and alerted the fire brigade. tree →
• The guard dog was alert all night. tree →
• After a good sleep you feel more alert in class. tree →
• Police are on high alert during the parade. tree →
• His alert eye caught sight of a rawhide rope staked to the water's brink, which led away toward a small round hut in the distance. tree →

Note

«Alert» as an adjective is the opposite of «sleepy» or «careless». «Alert someone to something» = warn them about it. Say «an alert» (starts with a vowel sound). Not to be confused with «allergy».