=Intermediate Range Ballistic Missile 中程弹道导弹

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]