The term 'VAQUERO's Weapon' is a crossword solution that can be filled in with the word 'Bola', which is a four-letter word. A bola is a throwing weapon used by South American cowboys, or VAQUERO's, to capture animals. It consists of two or more weights connected by a cord, which is thrown at the target and wraps around it. The bola is still used today by gauchos, or South American cowboys, to capture cattle.