A weapon, arm, or armament is any implement or device that is used to deter, threaten, inflict physical damage, harm, or kill. Weapons are used to increase the efficacy and efficiency of activities such as hunting, crime (e.g., murder), law enforcement, self-defense, warfare, or suicide.
weap•on (ˈwɛp ən) n. 1. any instrument or device used for attack or defense in a fight or in combat. 2. anything used against an opponent, adversary, or victim: the weapon of satire. 3. any part or organ serving for attack or defense, as claws, horns, teeth, or stings.