vigilance

名词 vigilance:

1. the process of paying close and continuous attention
   同义词：watchfulness, wakefulness, alertness
2. vigilant attentiveness
   同义词：watchfulness, weather eye

1. The price of liberty is eternal vigilance.
   自由的代价是永久提高警惕。
2. You cannot afford to relax your vigilance for a moment.
   警惕性是万万不可放松的。
3. In spite of vigilance a polar bear escape from the zoo.
   尽管警戒很严，北极熊还是逃出了动物园。
4. Police's vigilance was eventually rewarded.
   警方时时警戒终有所获。

vig.i.lance

n.（名词）
Alert watchfulness.
警惕，警戒：警惕的观察