The Collaborative International Dictionary of English v.0.48:
Argus \Ar"gus\, prop. n. [L. Argus, Gr. ?.]
1. (Myth.) A fabulous being of antiquity, said to have had a
hundred eyes, who has placed by Juno to guard Io. His eyes
were transplanted to the peacock's tail.
2. One very vigilant; a guardian always watchful.
3. (Zool.) A genus of East Indian pheasants. The common
species (Argus giganteus) is remarkable for the great
length and beauty of the wing and tail feathers of the
male. The species Argus Grayi inhabits Borneo.