Spine /(?)/

Spine

n.
  1. A sharp appendage to any of a plant; a thorn. (Bot.)
  2. A rigid and sharp projection upon any part of an animal. (Zool.)
  3. The backbone, or spinal column, of an animal; -- so called from the projecting processes upon the vertebrae. (Anat.)
  4. Anything resembling the spine or backbone; a ridge.