What does "sciatica" mean?

Sciatica: Neuralgia of the sciatic nerve, an affection characterized by paroxysmal attacks of pain in the buttock, back of the thing, 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 adjoininhg. See Ischiadic passion, under Ischiadic.