According to the Merriam-Webster dictionary, a gun could mean "a piece of ordnance usually with high muzzle velocity and comparatively flat trajectory," " a portable firearm," or "a device that throws a projectile."

Gunpowder and firearm historian Kenneth Chase defines "firearms" and "guns" in his Firearms: A Global History to 1700 as "gunpowder weapons that use the explosive force of the gunpowder to propel a projectile from a tube: cannons, muskets, and pistols are typical examples."