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late 14c., from Medieval Latin sciatica, in sciatica passio "sciatic disease," fem. of sciaticus "sciatic," corruption of Latin ischiadicus "of pain in the hip," from Greek iskhiadikos, from iskhias (genitive iskhiados) "pain in the hips," from iskhion "hip joint."
sciatica sci·at·i·ca (sī-āt'ĭ-kə)
Pain along the sciatic nerve that radiates from the lower back to the buttocks and back of the thigh and is usually caused by a herniated disk of the lumbar region of the spine.