Source : Webster's Revised Unabridged Dictionary (1913)

Malleolus \Mal*le"*o*lus\, n.; pl. {Malleoli}. [L., dim. of
   malleus hammer.]
   1. (Anat.) A projection at the distal end of each bone of the
      leg at the ankle joint. The malleolus of the tibia is the
      internal projection, that of the fibula the external.

   2. `` A layer, '' a shoot partly buried in the ground, and
      there cut halfway through.