Source : Webster's Revised Unabridged Dictionary (1913)

Nervousness \Nerv"ous*ness\, n.
   State or quality of being nervous.

Source : WordNet®

nervousness
     n 1: the anxious feeling you have when you have the jitters [syn:
           {jitteriness}, {jumpiness}, {restiveness}]
     2: an uneasy psychological state; "he suffered an attack of
        nerves" [syn: {nerves}]
     3: a sensitive or highly strung temperament