vigilant

/ˈvi-jə-lənt/

Middle English (Scots), from Latin vigilant-, vigilans, from present participle of vigilare to keep watch, stay awake, from vigil awake

adjective

  1. alertly watchful especially to avoid danger

watchful vigilant wide-awake alert mean being on the lookout especially for danger or opportunity. watchful is the least explicit term. vigilant suggests intense, unremitting, wary watchfulness.

adjective

  1. extremely or excessively vigilant : highly or abnormally alert to potential danger or threat

After an accident or an assault, most people tend to feel unsafe, to have a reduced startle threshold, and to be hypervigilant.

idiom

  1. while being watched by (someone)

The students did their work {phrase}under the watchful/vigilant eye of{/phrase} their teacher.