Definition of triennial

The word "triennial" derives from the Latin prefix "tri-," meaning "three," and the suffix "-al," meaning "pertaining to." Its origin can be traced back to the Middle Ages, where it was used to describe events or processes that occurred once every three years. In medieval Europe, the term was particularly associated with religious festivals and ceremonies. For example, many towns and cities across Europe held a "triennial procession," which involved a religious parade that took place every three years. The Italian city of Siena still hosts a famous triennial horse racing event, known as the Palio di Siena, which dates back to the 17th century. Outside of religious contexts, the term "triennial" was also used to describe certain legal or political traditions. For example, in some medieval European societies, court trials were held every three years in order to address any outstanding legal cases. In modern usage, the word "triennial" is still commonly used to describe events or processes that take place over a three-year period, particularly in the context of art exhibitions, international conventions, and academic research initiatives. Nonprofit organizations may also describe their fundraising campaigns as triennial, meaning that they occur every three years. The broader meaning of the term, as a short descriptor for events or processes that happen every three years, has remained largely unchanged since its inception in the Middle Ages.