sentinel

• 名词，指被派去观察或警戒的人或物，用于监视可能发生的事件或危险；也指执行此类任务的士兵或哨兵。

A noun referring to a person or thing employed to keep watch for some anticipated event or danger.

1. Guard or WatchpersonB2formal

   A person employed to keep watch for some anticipated event, such as an attack or danger.

   哨兵

   • The sentinel stood guard at the castle gate all night.
   • A sentinel was posted on the hill to watch for approaching enemies.
   • The sentinel's duty was to alert the camp of any threats.

   同义词guardlookoutpicketsentrywatcherwatchman

2. Protective SystemC1formal

   A device or system that monitors for specific events or dangers.

   哨兵系统

   • The security system acts as a sentinel against intruders.
   • Software sentinels monitor network traffic for suspicious activity.
   • The early warning system is a sentinel for natural disasters.

   同义词detectorguardianmonitorsensorwatchdog