An Intermediate Range Ballistic Missile. A ballistic missile with a range of between 100 and perhaps 1500 nautical miles. Examples include the U.S. Jupiter (the missile systems removed from Turkey in 1963, some say in return for the removal of Soviet missiles from Cuba during the Cuban Missile Crisis); the ubiquitous SCUD missile and its variants, and the North Korean No-dong and early varieties of the Taepo-dong. India has the Agni; Russia moved on to the SS-20 Saber and simliar models. sothazi reminds me that in fact the first operational modern ballistic missile, the V2, was in fact an IRBM.