sciatic

1. Of or relating to the ischium or to the region of the hipbone in which it is located.
2. Of or relating to sciatica.

[French sciatique, from Old French, from Medieval Latin sciaticus, alteration of Latin ischiadicus, from Greek iskhiadikos, from iskhias, iskhiad-, sciatica, from iskhion, hip.]

1. Of or relating to the ischium or to the region of the hipbone in which it is located.
2. Of or relating to sciatica.

Pertaining to the ischium.

• s. nerve — a large nerve extending from the lumbosacral plexus down the thigh, with branches throughout the lower leg and foot. It is the widest nerve of the body and one of the longest.
• s. nerve degeneration — occurs during parturition in cows due to passage of a large fetus through the pelvic canal causing pressure and subsequent degeneration of one or both sciatic nerves leading to posterior paresis or paralysis.
• s. nerve paralysis — injury to the sciatic nerve, commonly during difficult parturition in heifers, causes weakness or paralysis of one hindleg and the animal is recumbent. See also maternal obstetric paralysis.

The adjective has 2 meanings:

Meaning #1: relating to or caused by or afflicted with sciatica
  Pertains to noun: sciatica (meaning #1)

Meaning #2: of or relating to the ischium (or the part of the hipbone containing it)
  Pertains to noun: hip (meaning #3)