A gallery or arcade above the arches of the nave, choir, and transepts of a church.
- ‘It's a balustraded eyrie in the triforium, the narrow gallery 60 feet above the ground.’
- ‘In ecclesiastical buildings, the triforium, a windowless gallery above the main arcade, was of great importance, largely for structural reasons, in contrast to the enlarged clerestory of Gothic architecture.’
- ‘The church has been altered to form an auditorium with partly raked seating in the nave and exhibition spaces in the aisles and triforium.’
- ‘The triforium zone of the basilica features a cycle of over thirty frescoes of the life and legend of Peter, executed in about 1300 and credited to Deodato Orlandi.’
- ‘A vast white room, it was, with a wide, white triforium lined with white canvas mattresses.’
Early 18th century: from Anglo-Latin, of unknown origin.