Oriel
Origin
Old French oriol ("gallery, corridor"), Late Latin oriolum ("portico, hall"), probably from Latin aureolus ("gilded"), applied to an apartment decorated with gilding. See oriole.
Usage notes
There is no generally accepted difference between a bay window and an oriel. In the United States, the latter name is often applied to bay windows which are small, and either polygonal or round, and to those that are corbelled out from the wall instead of resting on the ground.