ballistic missile \ballis"tic mis`sile\, n.
   a rocket-propelled missile of long range which is guided only
   during the powered portion of its flight, which usually takes
   only a small part of the total flight time; -- contrasted
   with guided missile.

   note: ballistic missiles are sometimes referred to by their
         range, such as an

   intercontinental ballistic missile icbm or an

   intermediate range ballistic missile irbm.
      pjc
see also:
guided missile intercontinental ballistic missile icbm intermediate range ballistic missile irbm