Rose Window, Church of St. Ouen, Rouen
A Rose window (or Catherine window) is often used as a generic term applied to a circular window, but is especially used for those found in churches of the Gothic architectural style and being divided into segments by stone mullions and tracery. The name "rose window" was not used before the 17th century and according to the Oxford English Dictionary, among other authorities, comes from the English flower name rose.
A. D. F. Hamlin College Histories of Art History of Architecture (New York, NY: Longmans, Green, and Co., 1915)
Courtesy the private collection of Roy Winkelman