noun fire·arm \ˈfī(-ə)r-ˌärm\

  • small arms weapon, as a rifle or pistol, from which a projectile is fired by gunpowder.
  • A device which, on demand by activating some sort of switch like a trigger, ignites a very-rapidly burning propellant or an explosive, expels a projectile such as a bullet, or projectiles such as shot, from a tubular barrel (or barrels) with sufficient force as to cause acute bodily harm to the target, animal, or person which it hits.
  • A rifle, shotgun or handgun using gunpowder as a propellant. By federal definition, under the 1968 Gun Control Act. Air guns are not, by definition, firearms.