IRBM

from The Collaborative International Dictionary of English v.0.48
ballistic missile \bal*lis"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]
    

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