Source : Webster's Revised Unabridged Dictionary (1913)

Polyspast \Pol"y*spast\, n. [L. polyspaston, fr. Gr. ?, fr. ?
   drawn by several cords; poly`s many + ? to draw: cf. F.
   polyspaste.] (Surg.)
   A machine consisting of many pulleys; specifically, an
   apparatus formerly used for reducing luxations.