The Collaborative International Dictionary of English v.0.48:

nervy \nerv"y\ (n[~e]rv"[y^]), a. [Compar. nervier
   (n[~e]rv"[i^]*[~e]r); superl. nerviest.]
   1. Strong; sinewy. "His nervy knees." --Keats.
      [1913 Webster]

   2. Offensively bold or presumptuous; insolent; cheeky; pushy.
      [PJC]

   3. Exhibiting courage or daring; bold; plucky.
      [PJC]

   4. Nervous[6]; apprehensive; edgy[1].
      [PJC]