The Collaborative International Dictionary of English v.0.48:

Artillery \Ar*til"ler*y\, n. [OE. artilrie, OF. artillerie,
   arteillerie, fr. LL. artillaria, artilleria, machines and
   apparatus of all kinds used in war, vans laden with arms of
   any kind which follow camps; F. artillerie great guns,
   ordnance; OF. artillier to work artifice, to fortify, to arm,
   prob. from L. ars, artis, skill in joining something, art.
   See Art.]
   1. Munitions of war; implements for warfare, as slings, bows,
      and arrows. [Obs.]
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            And Jonathan gave his artillery unto his lad. --1
                                                  Sam. xx. 40.
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   2. Cannon; great guns; ordnance, including guns, mortars,
      howitzers, etc., with their equipment of carriages, balls,
      bombs, and shot of all kinds.
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   Note: The word is sometimes used in a more extended sense,
         including the powder, cartridges, matches, utensils,
         machines of all kinds, and horses, that belong to a
         train of artillery.
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   3. The men and officers of that branch of the army to which
      the care and management of artillery are confided.
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   4. The science of artillery or gunnery. --Campbell.
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   Artillery park, or Park of artillery.
      (a) A collective body of siege or field artillery,
          including the guns, and the carriages, ammunition,
          appurtenances, equipments, and persons necessary for
          working them.
      (b) The place where the artillery is encamped or
          collected.

   Artillery train, or Train of artillery, a number of
      pieces of ordnance mounted on carriages, with all their
      furniture, ready for marching.
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WordNet (r) 3.0 (2006):

artillery
    n 1: large but transportable armament [syn: artillery, heavy
         weapon, gun, ordnance]
    2: an army unit that uses big guns [syn: artillery, artillery
       unit]
    3: a means of persuading or arguing; "he used all his
       conversational weapons" [syn: weapon, artillery]

Easton's 1897 Bible Dictionary:

Artillery
   1 Sam. 20:40, (Heb. keli, meaning "apparatus;" here meaning
   collectively any missile weapons, as arrows and lances. In
   Revised Version, "weapons"). This word is derived from the Latin
   artillaria = equipment of war.