Source : Webster's Revised Unabridged Dictionary (1913)

Myotomy \My*ot"o*my\, n. [Myo- + Gr. ? to cut: cf. F. myotomie.]
   The dissection, or that part of anatomy which treats of the
   dissection, of muscles.

Source : WordNet®

myotomy
     n : surgical incision or division of a muscle