Source : Webster's Revised Unabridged Dictionary (1913)

Spadix \Spa"dix\, n.; pl. L. {Spadices}, E. {Spadixes}. [L., a
   palm branch broken off, with its fruit, Gr. ?.]
   1. (Bot.) A fleshy spike of flowers, usually inclosed in a
      leaf called a spathe.

   2. (Zo["o]l.) A special organ of the nautilus, due to a
      modification of the posterior tentacles.

Source : WordNet®

spadix
     n : the fleshy axis of a spike often surrounded by a spathe
     [also: {spadices} (pl)]