1.The science or art of hurling missile weapons by the use of an engine.
2.The science treating the motion of projectiles in flight, especially when they are in free fall within the earth's gravitational field.
3.The study of the characteristics of a cartridge fired from a firearm, and of the processes occurring during the discharge of a firearm.
4.The division within a police department which studies the characteristics of cartridges fired from a firearm; the ballistics department. The characteristics of the weapons and bullets fired may be used as evidence in criminal investigations.