1. Large-caliber weapons, such as cannon, howitzers, and missile launchers, that are operated by trained crews: "The branch of an army that specializes in the use of such weapons or artilleries."
2. The science of the use of guns; gunnery.
3. Weapons, such as catapults, arbalests, and other early devices, used for discharging missiles.
4. Etymology: from about 1386, "warlike munitions", from Old French artillerie, from artillier, "to provide with engines of war", which probably is from Middle Latin articulum, "art, skill"; a diminutive of Latin ars, artis, "art".

The sense of "engines for discharging missiles" (catapults, slings, bows, etc.) is from 1496; and that of "ordnance, large guns" is from 1533.