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.
The term “wheel window” is often applied to a window divided by simple spokes radiating from a central boss or opening, while the term “rose window” is reserved for those windows of more complex design which can be seen to bear similarity to a multi-petalled rose. A circular window without tracery, such as are found in many Italian churches, is referred to as an ocular window or oculus.
Rose windows are particularly characteristic of Gothic architecture and may be seen in all the major Gothic Cathedrals of Northern France. Their origins are much earlier and rose windows may be seen in various forms throughout the Medieval period. Their popularity was revived, with other medieval features, during the Gothic revival of the 19th century so that they are seen in Christian churches all over the world.