The Collaborative International Dictionary of English v.0.48:

Edgy \Edg"y\, a. [From Edge.]
   1. Easily irritated; sharp; as, an edgy temper.
      [1913 Webster]

   2. (Fine Arts) Having some of the forms, such as drapery or
      the like, too sharply defined. "An edgy style of
      sculpture." --Hazlitt.
      [1913 Webster]

WordNet (r) 3.0 (2006):

edgy
    adj 1: being in a tense state [syn: edgy, high-strung,
           highly strung, jittery, jumpy, nervy,
           overstrung, restive, uptight]