Source : Webster's Revised Unabridged Dictionary (1913)

Sciatica \Sci*at"i*ca\, n. [NL.] (Med.)
   Neuralgia of the sciatic nerve, an affection characterized by
   paroxysmal attacks of pain in the buttock, back of the thigh,
   or in the leg or foot, following the course of the branches
   of the sciatic nerve. The name is also popularly applied to
   various painful affections of the hip and the parts adjoining
   it. See {Ischiadic passion}, under {Ischiadic}.

Source : WordNet®

sciatica
     n : neuralgia along the sciatic nerve