Classical Mythology . a giant with 100 eyes, set to guard the heifer Io

his eyes were transferred after his death to the peacock's tail.

a son of Phrixus and builder of the Argo.

(in the Odyssey ) Odysseus' faithful dog, who recognized his master after twenty years and immediately died.

any observant or vigilant person; a watchful guardian.

( lowercase ) Also, argus pheasant. any of several brilliantly marked Malayan pheasants of the Argusianus or Rheinardia genera.