Epidural space:

epidural space.

usually refers to a space in the spine (epidural space in the skull generally only exists due to pathology), the epidural space is a space between the dura and the bone of the vertebral column. It is filled with cerebrospinal fluid; often analgesics or anesthetics are injected here.

Watch this 2-Minute Neuroscience video to learn more about the spinal cord.