Source : Webster's Revised Unabridged Dictionary (1913)

Chiton \Chi"ton\, n. [Gr. ? a chiton (in sense 1).]
   1. An under garment among the ancient Greeks, nearly
      representing the modern shirt.

   2. (Zo["o]l.) One of a group of gastropod mollusks, with a
      shell composed of eight movable dorsal plates. See
      {Polyplacophora}.

Source : WordNet®

chiton
     n 1: a woolen tunic worn by men and women in ancient Greece
     2: primitive elongated bilaterally symmetrical marine mollusk
        having a mantle covered with eight calcareous plates [syn:
         {coat-of-mail shell}, {sea cradle}, {polyplacophore}]