alert

keep sb

Drinking coffee helps keep me alert during long study sessions.

immediately, instantly, suddenly

When the dog heard the doorbell, it became immediately alert and started barking.

mentally

Even after working all night, Sarah remained mentally alert during the important meeting.

to

The security guard remained alert to any suspicious activity throughout the night.

red

The hospital went on red alert when the emergency room suddenly became overwhelmed with patients.

bomb, fire, flood, pollution, security

The city issued a flood alert after heavy rain caused the river to rise dangerously.

issue, put out, raise, sound

The airport security team issued an alert after they discovered a suspicious package near the terminal.

call off

The fire department called off the alert after they confirmed there was no danger in the building.

go out

When the storm warning came through, an emergency alert went out to all residents in the area.

~ for

Police officers stay on the alert for any signs of trouble in the neighborhood.

be on full alert

The hospital staff remained on full alert during the emergency situation yesterday.

keep/put/place sb on full alert

The security team kept all staff on full alert after the suspicious package was discovered.

a state of alert

The hospital staff remained in a state of alert throughout the night due to the emergency.