vigilant Meaning, Definition & Usage

  1. adjective satellite carefully observant or attentive; on the lookout for possible danger
    wakeful; open-eyed; argus-eyed.
    • a policy of open-eyed awareness
    • the vigilant eye of the town watch
    • there was a watchful dignity in the room
    • a watchful parent with a toddler in tow

WordNet

Vig"i*lant adjective
Etymology
L. vigilans, -antis, p. pr. of vigilare to watch, fr. vigil awake: cf. F. vigilant. See Vigil.
Definitions
  1. Attentive to discover and avoid danger, or to provide for safety; wakeful; watchful; circumspect; wary. "Be sober, be vigilant." 1 Pet. v. 8.
    Sirs, take your places, and be vigilant. Shak.

Webster 1913