As used in WPCC 9.20.020, the term “gun” shall include any firearm, rifle, shotgun, revolver, pistol, air gun, air rifle, or any similar mechanism by whatever name known which is designed to expel a projectile through a gun barrel by the action of any explosive, gas, compressed air, spring, or elastic. [Ord. 08-21-2012B § 1; Ord. 10-18-2011A § 1. Code 2000 § 6-6-1].