Source : Webster's Revised Unabridged Dictionary (1913)

Lithotomy \Li*thot"o*my\, n. [L. lithotomia, Gr. ?: cf. F.
   lithotomie.] (Surg.)
   The operation, art, or practice of cutting for stone in the
   bladder.

Source : WordNet®

lithotomy
     n : surgical removal of a stone (calculus)