Source : Webster's Revised Unabridged Dictionary (1913)

      Our aristocratic class does not firmly protest against the
      unfair treatment of Irish Catholics, because it is nervous
      about the land.                             --M. Arnold.

   {Nervous fever} (Med.), a low form of fever characterized by
      great disturbance of the nervous system, as evinced by
      delirium, or stupor, disordered sensibility, etc.

   {Nervous system} (Anat.), the specialized co["o]rdinating
      apparatus which endows animals with sensation and
      volition. In vertebrates it is often divided into three
      systems: the central, brain and spinal cord; the
      peripheral, cranial and spinal nerves; and the
      sympathetic. See {Brain}, {Nerve}, {Spinal cord}, under
      {Spinal}, and {Sympathetic system}, under {Sympathetic},
      and Illust. in Appendix.

   {Nervous temperament}, a condition of body characterized by a
      general predominance of mental manifestations. --Mayne.

Source : WordNet®

nervous system
     n : the sensory and control apparatus consisting of a network of
         nerve cells [syn: {systema nervosum}]