#structural warfare

• Arquebus — An individual, portable, long-barreled firearm with a matchlock mechanism, invented in the 15th century, representing one of the first firearms widely used in European infantry. Structurally, it was heavy, muzzle-loaded, and possessed a powerful recoil, often requiring a forked rest support during firing.
• Arenar — An ancient Roman gladiator who fought in the amphitheater arenas; a slave or convict sent to death in public circus spectacles. As a rare adjective, it describes a structural element, a tool, or a person directly related to cleaning, preparing, or managing the sand (arena) within performance spaces or extraction quarries.