Gun up! (3)

A gun is a device that propels a projectile using pressure or explosive force. The projectiles are typically solid, but can also be pressurized liquid, or gas. Solid projectiles may be free-flying or tethered. A large-caliber gun is also called a cannon, while a hand-held gun may be called a firearm. Guns were designed as weapons for military use, and then found use in hunting.