The DICT Development Group

  Argus-eyed \Ar"gus-eyed\, a.
     Extremely observant; watchful; sharp-sighted.
     [1913 Webster]

  argus-eyed
      adj 1: having very keen vision; "quick-sighted as a cat" [syn:
             argus-eyed, hawk-eyed, keen-sighted, lynx-eyed,
             quick-sighted, sharp-eyed, sharp-sighted]
      2: 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, vigilant, wakeful]