alert

• 形容人能够迅速察觉并反应周围情况；警觉、机敏且头脑清醒。

Describes someone who is quick to notice and respond to things; watchful and mentally active.

1. Watchful and attentiveB1formal

   Quick to notice any unusual and potentially dangerous or difficult circumstances; vigilant.

   警觉的

   • The security guard remained alert throughout the night.
   • Drivers should be alert for pedestrians crossing the street.
   • She was alert to any signs of trouble.

   同义词attentiveawareobservanton guardsharpvigilantwarywatchful

   反义词distractedheedlessinattentiveobliviousunawareunobservant

2. Mentally activeB1formal

   Quick to think and understand; mentally sharp.

   警觉的

   • After a good night's sleep, he felt more alert.
   • The students were alert and ready for the quiz.
   • Caffeine helps keep me alert during long meetings.

   同义词astuteawakebrightclearheadedperceptivequick-wittedsharp

   反义词dullobtuseslowstupid

• 名词，指警告信号、通知，或面对潜在危险、紧急情况或重要信息时的戒备状态。

A noun referring to a warning signal, notification, or state of readiness in response to potential danger, urgency, or important information.

1. Warning signalB1formal

   A notification or signal that warns of danger or a problem.

   警报

   • The weather service issued a storm alert for the coast.
   • The fire alarm is a critical alert in the building.
   • The government sent an alert about the approaching hurricane.

   同义词advisoryalarmbeaconcautionnotificationsignalsirenwarning

2. State of readinessB2formal

   A period of heightened vigilance or preparedness.

   戒备状态

   • The military was placed on high alert after the threat.
   • The hospital remained on alert for potential emergencies.
   • The security team maintained a constant alert during the event.

   同义词awarenesspreparednessreadinessvigilancewarinesswatchfulness

• 动词，表示提醒某人注意危险、问题或重要情况，或引起某人对某事的注意。

A verb used to indicate the act of warning someone about a danger, problem, or important situation, or making someone aware of something.

1. Warn or notifyB1formal

   To warn someone about a danger, problem, or important situation.

   警告

   • The police alerted the public about the storm.
   • She alerted her colleagues to the security breach.
   • The system alerts users when a new update is available.

   同义词apprisecautionforewarninformnotifysignaltip offwarn

2. Make awareB1formal

   To make someone aware of something important or urgent.

   提醒

   • The doctor alerted the patient to the risks of the surgery.
   • He alerted the team to the deadline change.
   • The news alerted everyone to the potential crisis.

   同义词apprisecautionforewarninformnotifysignaltip offwarn

   反义词concealdeceivehideignoremisleadneglectsuppress