Pertaining to nerves or the nervous system at large; nervous.Specifically, of or relating to the cerebrospinal nervous system of a vertebrate.Situated on that side of the body, with reference to the vertebral axis, on which the brain and spinal cord lie; dorsal or tergal: opposed to ventral, sternal, visceral, or hemal.In physiology, done or taking place in the nerves.n. One of the bony plates that lie upon and fuse with the summit of the spinous process and take part in the formation of the carapace of a turtle.