A projectile was an object propelled by an external force and in motion. A projectile could be shot or launched from a projectile weapon such as an arrow from a bow or crossbow, a rock from a sling, a bullet from a firearm, a rocket from a rocket launcher, or a shell from artillery. A projectile could also be any thrown or kicked object such as a ball, dart, or spear.
In 2267, the shuttlecraft Galileo's gathering speed was multiplied geometrically due to the magnetic potential of the Murasaki Effect which caused the shuttle to crash land on Taurus II. Lieutenant Boma likened the shuttlecraft's occupants being shot into the center of the Murasaki Effect to that of a projectile. (TOS: "The Galileo Seven")
Later that year, Spock claimed that diamonds were the hardest known substance and would make formidable projectiles when impelled by the sufficient force of gunpowder. (TOS: "Arena")