The Collaborative International Dictionary of English v.0.48:

Antares \An*ta"res\, n. [Gr. ?; ? similar to + ? Mars. It was
   thought to resemble Mars in color.]
   The principal star in Scorpio: -- called also the Scorpion's
   Heart.
   [1913 Webster] antiarthritic

WordNet (r) 3.0 (2006):

Antares
    n 1: the brightest star in Scorpius