A "tercio" is a traditional unit of measurement in Spanish bullfighting, representing one-third of the entire fight. The event is divided into three distinct parts: the tercio de varas, where the bull is tested for strength; the tercio de banderillas, where colorful barbed sticks are placed in the bull's back; and the tercio de muerte, where the matador ultimately kills the bull. Each tercio has its own specific rituals and techniques. The concept of tercio is not limited to bullfighting; it can also refer to a third of something in various contexts. In music, for example, a tercio can denote a third interval. The term is derived from the Spanish word for "third," highlighting its significance in both cultural and mathematical contexts.