For the purposes of this article, the following words and phrases shall have the meanings respectively ascribed to them by this section:
Any gun, rifle or pistol, by whatever name known, which is designed to expel a projectile by the action of compressed air or gas, or by the action of a spring or elastic, but does not mean a firearm.
Any person engaged in the business of selling at retail or renting any of the articles designated in this section.
(Ordinance 225, § 1)