The Collaborative International Dictionary of English v.0.48:

Spinal \Spi"nal\, a. [L. spinalis, fr. spina the spine: cf. F.
   spinal. See Spine.]
   1. (Anat.) Of, pertaining to, or in the region of, the
      backbone, or vertebral column; rachidian; vertebral.
      [1913 Webster]

   2. Of or pertaining to a spine or spines.
      [1913 Webster]

   Spinal accessory nerves, the eleventh pair of cranial
      nerves in the higher vertebrates. They originate from the
      spinal cord and pass forward into the skull, from which
      they emerge in company with the pneumogastrics.

   Spinal column, the backbone, or connected series or
      vertebrae which forms the axis of the vertebrate skeleton;
      the spine; rachis; vertebral column.

   Spinal cord, the great nervous cord extending backward from
      the brain along the dorsal side of the spinal column of a
      vertebrate animal, and usually terminating in a threadlike
      appendage called the filum terminale; the spinal, or
      vertebral, marrow; the myelon. The nervous tissue consists
      of nerve fibers and nerve cells, the latter being confined
      to the so-called gray matter of the central portions of
      the cord, while the peripheral white matter is composed of
      nerve fibers only. The center of the cord is traversed by
      a slender canal connecting with the ventricles of the
      brain.
      [1913 Webster]

WordNet (r) 3.0 (2006):

spinal
    adj 1: of or relating to the spine or spinal cord; "spinal
           cord"; "spinal injury"
    n 1: 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 [syn:
         spinal anesthesia, spinal anaesthesia, spinal]