damage-absorbing protective energy field in science fiction or video games

当敌方发起进攻时，飞船会自动开启护盾。

noun · person, organization, or principle providing protection or security

法律是维护社会公平正义的坚强护盾。

physical protective gear used in historical combat to intercept attacks

古代士兵手持护盾挡住了敌人的进攻。