A quatrefoil is a decorative element consisting of a symmetrical shape which forms the overall outline of four partially overlapping circles of the same diameter. It is found in art, architecture, heraldry and traditional Christian symbolism. The word 'quatrefoil' means "four leaves", from the Latin quattuor, "four", plus folium, "leaf"; the term refers specifically to a four-leafed clover, but applies in general to four-lobed shapes in various contexts. In recent years, several luxury brands have attempted to fraudulently assert creative rights related to the symbol, which naturally predates any of those brands' creative development. A similar shape with three rings is called a trefoil, while a shape with five is a cinquefoil.

Tracery is an architectural device by which windows are divided into sections of various proportions by stone bars or ribs of moulding. Most commonly, it refers to the stonework elements that support the glass in a window. The purpose of the device is practical as well as decorative, because the increasingly large windows of Gothic buildings needed maximum support against the wind. The term probably derives from the tracing floors on which the complex patterns of windows were laid out in late Gothic architecture. Tracery can be found on the exterior of buildings as well as the interior.