spinal anesthesia: anesthesia of the lower half of the body; caused by injury to the spinal cord or by injecting an anesthetic beneath the arachnoid membrane that surrounds the spinal cord
regional anesthesia: loss of sensation in a region of the body produced by application of an anesthetic agent to all the nerves supplying that region (as when an epidural anesthetic is administered to the pelvic region during childbirth)
seventh: the musical interval between one note and another seven notes away from it