Source : Webster's Revised Unabridged Dictionary (1913)

Ballistics \Bal*lis"tics\, n. [Cf. F. balistique. See
   {Ballista}.]
   The science or art of hurling missile weapons by the use of
   an engine. --Whewell.

Source : WordNet®

ballistics
     n 1: the trajectory of an object in free flight [syn: {ballistic
          trajectory}]
     2: the science of flight dynamics