A trefoil is a graphic form composed of the outline of three overlapping rings, used in architecture, Pagan and Christian symbolism, among other areas. The term is also applied to other symbols with a threefold shape. A similar shape with four rings is called a quatrefoil.
Evolution of layout of Maltese Megalithic temples; Skorba (upper right) has a typical trefoil plan
Croatian trefoil badge worn by Royal Croatian Home Guard during Austria-Hungary, depicting oak leaves
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.
Quatrefoil above the west door of Croyland Abbey showing in relief scenes from the life of Saint Guthlac
Quatrefoil window at the St. Petrus parish church in Peterslahr, Germany
Barbed quatrefoil containing relief of The Sacrifice of Isaac (1401) by Lorenzo Ghiberti for the Baptistry, Florence. Bargello Museum, Florence