Iconography:
Saint Catherine of the Wheel
Illustrated
Architecture
Dictionary
Wheel window / Catherine Wheel
A round window with muntins radiating from the center, as in the spokes of a wheel.
Catherine wheel: Saint Catherine was tortured on a wheel by the Emperor Maxentius for refusing to renounce her Christian faith. The wheel broke and Catherine was eventually beheaded instead.
Earliest form of the rose window
Found especially in Italy and Germany
Found in Romanesque style churches and later in Gothic and Gothic Revival styles
Examples from Buffalo architecture: