The term 'Arsenal Stockpile' refers to a large collection of weapons and AMMUNITION. The crossword solution for the term is 'AMMO', which is an abbreviation for 'AMMUNITION'. AMMUNITION is a type of explosive material used in firearms, artillery, and other weapons. It is typically composed of a propellant, such as gunpowder, and a projectile, such as a bullet or shell. An arsenal stockpile is a large collection of weapons and AMMUNITION that is stored for military use.