The Collaborative International Dictionary of English v.0.48:

Cestus \Ces"tus\, n. [L. cestus girdle, Gr. ?, lit., stitched,
   embroidered.]
   1. (Antiq.) A girdle; particularly that of Aphrodite (or
      Venus) which gave the wearer the power of exciting love.
      [1913 Webster]

   2. (Zool.) A genus of Ctenophora. The typical species
      (Cestus Veneris) is remarkable for its brilliant
      iridescent colors, and its long, girdlelike form.
      [1913 Webster]