alert

Definition:
1. Condition of heightened watchfulness or preparation for action.
2. A warning serves to make you more alert to danger.
3. An automatic signal (usually a sound) warning of danger.
4. Warn or arouse to a sense of danger or call to a state of preparedness.
5. Very attentive or observant.
6. Mentally responsive.

Use 'alert' in a sentence:

1. All the St. Louis hospitals are on red alert.
2. When the system thinks it's being jammed, it'll notify you via push alert .
3. There were 15 minutes between the first air raid alert and the sounding of the all-clear signal.
4. The coastguard was alerted.
5. Neighbours heard the sound of rifle fire and alerted the police.
6. SATAN has done more to alert people to the risks than cause new disorder.
7. I was hoping he'd alert the police.
8. I managed to walk around unchallenged for 10 minutes before an alert nurse spotted me.
9. He remembered afterward how intensely wide awake and alert he had thought he was.
10. Sirens sounded an end to the red alert.
11. The armed forces were on high alert to guard against any retaliation.
12. Due to a security alert, this train will not be stopping at Oxford Circus.
13. There has been criticism of how his administration handled last week's terrorism alert.
14. Alerted by a noise downstairs, he sat up and turned on the light.
15. You can be alert, even though the intensity of the stimulus is quite low.
16. He wanted to alert people to the activities of the group.
17. For example, fear can alert us to possible danger.
18. All the Plymouth hospitals are on red alert.
19. This is the sign used to alert drivers that there is a playground nearby.
20. We become more energetic, more alert, better able to take effective action.
21. The attack was unsuccessful and served only to alert the enemy.
22. The cat is alert to every sound and movement.
23. He had been spotted by an alert neighbour.
24. They want to be on the alert for similar buying opportunities.
25. They were quiet during the alert.
26. Just keeping you awake and alert apparently isn't enough of a benefit.
27. "Sharp" meant genuinely discerning, alert, acute rather than quick-witted or clever.
28. The all clear was sounded about 10 minutes after the alert was given.
29. More than 5 000 troops have been placed on (full) alert.
30. Soldiers and police have been put on alert.
31. They were up and alert and ready, evidently, whoever they were!
32. Bedrooms are fitted with alarm pull cords to alert the manager in an emergency.
33. An alert should appear, informing you to first select an item from the grid.
34. Two alert scientists spotted the mistake.
35. Following the bomb blast, local hospitals have been put on red alert.
36. More than 5 000 troops have been placed on alert.
37. Her expression was watchful and alert.
38. The security alert brought the airport to a standstill.
39. Suddenly he found himself awake and fully alert.
40. We all have to stay alert.
41. The stamp of hoofs alerted Isabel.
42. Her whole bearing was alert.
43. The bank is alert to the danger.
44. The baby is very mentally alert.
45. When you click the trigger, it pops up an alert.
46. Install a CO detector to alert you of the presence of the deadly, odorless, colorless gas.
47. Police are warning the public to be on the alert for suspicious packages.
48. Troops in the Philippines have been put on full alert in anticipation of trouble during a planned general strike.
49. If our environment cools, then messages from the skin alert the body's thermostat.