ORIEL, in architecture, a projecting bay window on an upper storey, which is carried by corbels or mouldings. It is usually polygonal or semicircular in plan, but at Oxford in some of the colleges there are examples which are rectangular and rise through two or three storeys. In Germany it forms a favourite feature, and is sometimes placed at the angle of a building, carried up through two or three floors and covered with a loity roof. The oriel is also said to have been provided as a recess for an altar in an oratory or small chapel. In the 15th century oriels came into general use, and arc frequently found over entrance gateways.
The origin of the word is unknown. The suggested derivation from Lat. aureolum, with the supposed meaning of a gilded chamber or room, is not, according to the New English Dictionary, borne out by any historical evidence, and early French forms - such as eurieul - do not point to an origin in a word beginning with aic. Du Cange (Glossarium, s.v. Orioluni) quotes Matthew of Paris (1251, Vitac Abbatum S. Albani): adjacet atrium nobilissiniiim in introiiu, quod porticus vcl Oriolum appcllatur; and also a French use of 1338, where a licence to build an oriol is granted to one Jehan Bourgos. The earliest meaning seems to be a gallery, portico or corridor, and the application of the term to a particular form of window apparently arose from such a window being in an "oriel." In ComwaU " orrel" is still used of a balcony or porch at the head of an outside staircase leading to an upper story in a fisherman's cottage. The name of Oriel College, at Oxford, comes from a tenement known as Seneschal Hall or La Oriole, and granted to the college in 1327. There is no trace of the reason why the tenement was so called, but it would seem that it referred to one of the earlier applications of the word, to a gallery or porch, rather than to a window.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)