Projectile provided with means for altering its direction after it leaves its launching device. Almost all modern missiles are propelled by rocket or jet engines and have guidance mechanisms, usually incl. sensors, to help the missile find its target. Heat-seeking missiles, for example, carry infrared sensors that allow them to home in on the exhaust of jet engines.
An unmanned vehicle moving above the surface of the Earth whose trajectory or flight path is capable of being altered by an external or internal mechanism. See also aerodynamic missile; ballistic missile.