The Collaborative International Dictionary of English v.0.48:

Ballistic \Bal*lis"tic\, a.
   1. Of or pertaining to the ballista, or to the art of hurling
      stones or missile weapons by means of an engine.
      [1913 Webster]

   2. Pertaining to ballistics[2], or to a projectile in a
      gravitational field.
      [1913 Webster +PJC]

   3. frenzied; very angry; -- used mostly in the phrase

   go ballistic. [Colloq.]
      [PJC]

   Ballistic pendulum, an instrument consisting of a mass of
      wood or other material suspended as a pendulum, for
      measuring the force and velocity of projectiles by means
      of the arc through which their impact impels it.
      [1913 Webster]

WordNet (r) 3.0 (2006):

ballistic
    adj 1: relating to or characteristic of the motion of objects
           moving under their own momentum and the force of gravity;
           "ballistic missile"