Source : Webster's Revised Unabridged Dictionary (1913)

Sciatic \Sci*at"ic\, a. [F. sciatique, LL. sciaticus, from L.
   ischiadicus, Gr. ?. See {Ischiadic}.] (Anat.)
   Of or pertaining to the hip; in the region of, or affecting,
   the hip; ischial; ischiatic; as, the sciatic nerve, sciatic
   pains.

Sciatic \Sci*at"ic\, n. [Cf. F. sciatique.] (Med.)
   Sciatica.

Source : WordNet®

sciatic
     adj 1: relating to or caused by or afflicted with sciatica
     2: of or relating to the ischium (or the part of the hipbone
        containing it); "sciatic nerve"