Available Definitions:
1) n. - 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.
2) n. - Fig.: The means or instrument with which one contends against another; as, argument was his only weapon.
3) n. - A thorn, prickle, or sting with which many plants are furnished.