Source : Webster's Revised Unabridged Dictionary (1913)

Talus \Ta"lus\, n.; pl. {Tali}. [L., the ankle, the ankle bone.]
   1. (Anat.) The astragalus.

   2. (Surg.) A variety of clubfoot ({Talipes calcaneus}). See
      the Note under {Talipes}.

Source : WordNet®

talipes calcaneus
     n : talipes in which the toes are pointed upward and the person
         walks on the heel of the foot