Quarterfoil

A quatrefoil (anciently caterfoil) 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 Latin quattuor, four, plus folium, a leaf, referring specifically to a four-leafed clover, but applies in general to four-lobed shapes in various contexts. In recent years, a number of luxury brands have asserted copyright claims related to the symbol.

The quatrefoil enjoyed its peak popularity during the Gothic and Renaissance eras. It is most commonly found as tracery, mainly in Gothic architecture, where a quatrefoil often may be seen at the top of a Gothic arch, sometimes filled with stained glass. Although the design is often referred to as "of Islamic origin", there are examples of its use that precede the birth of Islam by almost 200 years. The Monastery of Stoudous in Istanbul was built in 462 AD, soon after Christianity became legal in the Byzantine Empire. The arches seen are the product of taking a regular quatrefoil and dividing it in half.)

In ancient Mesoamerica, the quatrefoil is frequently portrayed on Olmec and Mayan monuments, such as at La Blanca, Guatemala where it dates to approximately 850 BC. The quatrefoil depicts the opening of the cosmic central axis at the crossroads of the four cardinal directions, representing the passageway between the celestial and the underworld.

Another early example of a quatrefoil is found at Chalcatzingo, Morelos state, Mexico, the city that flourished between 700 BCE and 500 BCE. Both a full quatrefoil, and a partial portrayal of quatrefoil are found on monuments here. In the latter case, one half of a quatrefoil represents the opening of a cave where an important personage is seated. This cave opening represents a water source.

...
Wikipedia