[syn: weapon, artillery]
The Collaborative International Dictionary of English v.0.48:
Weapon \Weap"on\ (w[e^]p"[u^]n; 277), n. [OE. wepen, AS.
   w[=ae]pen; akin to OS. w[=a]pan, OFries. w[=e]pin, w[=e]pen,
   D. wapen, G. waffe, OHG. waffan, w[=a]fan, Icel. v[=a]pn,
   Dan. vaaben, Sw. vapen, Goth. w[=e]pna, pl.; of uncertain
   origin. Cf. Wapentake.]
   [1913 Webster]
   1. An instrument of offensive of defensive combat; something
      to fight with; anything used, or designed to be used, in
      destroying, defeating, or injuring an enemy, as a gun, a
      sword, etc.
      [1913 Webster]
            The weapons of our warfare are not carnal. --2 Cor.
                                                  x. 4.
      [1913 Webster]
            They, astonished, all resistance lost,
            All courage; down their idle weapons dropped.
                                                  --Milton.
      [1913 Webster]
   2. Fig.: The means or instrument with which one contends
      against another; as, argument was his only weapon.
      "Woman's weapons, water drops." --Shak.
      [1913 Webster]
   3. (Bot.) A thorn, prickle, or sting with which many plants
      are furnished.
      [1913 Webster]
   Concealed weapons. See under Concealed.
   Weapon salve, a salve which was supposed to cure a wound by
      being applied to the weapon that made it. [Obs.] --Boyle.
      [1913 Webster]
WordNet (r) 3.0 (2006):
weapon
    n 1: any instrument or instrumentality used in fighting or
         hunting; "he was licensed to carry a weapon" [syn:
         weapon, arm, weapon system]
    2: a means of persuading or arguing; "he used all his
       conversational weapons" [syn: weapon, artillery]
Moby Thesaurus II by Grady Ward, 1.0:
23 Moby Thesaurus words for "weapon":
   A-weapons, armament, arms, biological weapons,
   conventional weapons, cutting edge, deadly weapons, edge,
   edge tool, featheredge, instruments of destruction, knife-edge,
   missilery, munitions, musketry, nuclear weapons, ordnance,
   razor-edge, side arms, small arms, thermonuclear weapons, weaponry,
   weapons