vigilant (adj.)

  1. carefully observant or attentive; on the lookout for possible danger; 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

    [ Syn: argus-eyed , open-eyed , wakeful ]

The dictionary is based on the WordNet Electronic Lexical Database.
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