Source : Webster's Revised Unabridged Dictionary (1913)

Unrest \Un*rest"\, n.
   Want of rest or repose; unquietness; sleeplessness;
   uneasiness; disquietude.

         Is this, quoth she, the cause of your unrest!
                                                  --Chaucer.

         Can calm despair and wild unrest Be tenants of a single
         breast?                                  --Tennyson.

Source : WordNet®

unrest
     n 1: a state of agitation or turbulent change or development;
          "the political ferment produced a new leadership";
          "social unrest" [syn: {agitation}, {ferment}, {fermentation}]
     2: a feeling of restless agitation