The term 'Octagonal Order' refers to a type of architectural design that is characterized by an eight-sided structure. This type of order is often seen in churches, temples, and other religious buildings, as well as in some public buildings. The octagonal shape is thought to represent the idea of eternity, and it is believed to bring balance and harmony to the building. The term 'Octagonal Order' is derived from the Latin word for eight, octo.