trefoil#architecture

{{Short description|Artistic representation of three circular leaf shapes used in architecture}}

A trefoil ({{etymology|la|{{wikt-lang|la|trifolium}}|three-leaved plant}}) 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.

Architecture

=Ornamentation=

'Trefoil' is a term in Gothic architecture given to the ornamental foliation or cusping introduced in the heads of window-lights, tracery, and panellings, in which the centre takes the form of a three-lobed leaf (formed from three partially overlapping circles). One of the earliest examples is in the plate tracery at Winchester Cathedral (1222–1235). The fourfold version of an architectural trefoil is a quatrefoil.

A simple trefoil shape in itself can be symbolic of the Trinity,Our Christian Symbols by Friedrich Rest ({{ISBN|0-8298-0099-9}}), p. 17 while a trefoil combined with an equilateral triangle was also a moderately common symbol of the Christian Trinity during the late Middle Ages in some parts of Europe, similar to a barbed quatrefoil. Two forms of a trefoil combined with a triangle are shown below:

File:Trefoil-Architectural-Equilateral-Triangle-outlined.svg|alt=The outline of three interlocking circles with an equilateral triangle in the centre.|Outlined

File:Trefoil-Architectural-Equilateral-Triangle-interlaced.svg|alt=Three interlocking circles with a triangle in the centre, the full, interlocking lines of each now shown.|Interlaced

A dove, which symbolizes the Holy Spirit, is sometimes depicted within the outlined form of the trefoil combined with a triangle.

=Architectural layout=

In architecture and archaeology, a 'trefoil' describes a layout or floor plan consisting of three apses in clover-leaf shape, as for example in the Megalithic temples of Malta.

Particularly in church architecture, such a layout may be called a "triconchos".

File:Evolution du plan des temples copie.jpg|alt=A diagram of six examples of evolving temple floor plans, evolving clockwise, labelled {{lang|fr|Typologie des temples}} ("temple typology"). The floor plans evolve from small, simple rooms to much larger and more elaborate constructions.|Evolution of layout of Maltese Megalithic temples; Skorba (upper right) has a typical trefoil plan

File:Trikonchos.gif|alt=A triconchos floor plan, showing a wall with a door on the left side and three trefoil-like alcoves on the right.|A typical triconchos

Heraldry

The heraldic 'trefoil' is a stylized clover. It should not be confused with the figure named in French heraldry {{lang|fr|tiercefeuille}} ("threefoil"), which is a stylized flower with three petals, and differs from the heraldic trefoil in being not slipped.{{cite web |url=http://www.symbols.com/encyclopedia/24/2451.html |title=Online Encyclopedia of Western Signs and Ideograms - Symbol 24:51 |publisher=Symbols.com |date=1997–2006 |access-date=5 January 2010}}{{efn|The French terms '{{lang|fr|quartefeuille}}' and '{{lang|fr|quintefeuille}}' are translated as 'quatrefoils' and 'cinquefoils'.}}

File:Héraldique meuble trèfle 1.svg|Trefoil in heraldry

File:Blason famille fr Duprat.svg|Or a fess sable between three trefoils vert

File:Blason ville fr Boissy-sans-Avoir (Yvelines).svg|Gules a cross flory argent between four tiercefeuilles Or

File:16. varaždinska.jpg|Croatian trefoil badge worn by Royal Croatian Home Guard during Austria-Hungary, depicting oak leaves{{Cite book |first=Miroslav |last=Krleža |author-link=Miroslav Krleža |title=Croatian God Mars |chapter=Kraljevska ugarska domobranska novela |page=130 |edition=1 |location=Zagreb |publisher=Minerva |date=1933 |isbn=9788601013537 |url=https://books.google.com/books?id=yJE4AQAAIAAJ&q=trolistom+hrastovim |quote=U stara mirna vremena, kada je koji general držao smotru, pa se na cvjetnoj tratini skupili bataljoni zdravih četa u kalpacima i dolamama u paradi, svi okićeni trolistom hrastovim, svi ulašteni i izglačani, a trube udaraju i glazbe tresu zrakom, te tutnji kavalkada sa crvenim svilenim ruhom generaliteta i zelenim perjanicama, onda je bilo i neke inspiracije u tim puškohvatima. Svi stari soldati gledali su romantično na paradni osamnaesti augusta koji je počeo s topničkim salvama, a svršavao s lampionadom.}}

File:CroatianTrefoil.svg|Croatian trefoil used by the Axis-sympathetic Croatian Air Force Legion in World War II, formed from a defaced Balkenkreuz{{Cite web| title =History of 15./Jg 52| url =http://www.15jg52.com/history_real.asp| access-date =22 April 2011| url-status =dead| archive-url =https://web.archive.org/web/20110707055357/http://www.15jg52.com/history_real.asp| archive-date =7 July 2011}}

Symbols

Symmetrical trefoils are particularly popular as warning and informational symbols. If a box containing hazardous material is moved around and shifted into different positions, it is still easy to recognize the symbol,{{cite web|url=http://www.hms.harvard.edu/orsp/coms/BiosafetyResources/History-of-Biohazard-Symbol.htm|title=Committee on Microbiological Safety - HMS|website=www.hms.harvard.edu|access-date=2 April 2018|archive-date=16 July 2011|archive-url=https://web.archive.org/web/20110716160837/http://www.hms.harvard.edu/orsp/coms/BiosafetyResources/History-of-Biohazard-Symbol.htm|url-status=dead}} while the distinctive trefoil design of the recycling symbol makes it easy for a consumer to notice and identify the packaging the symbol has been printed on as recyclable. Easily stenciled symbols are also favored.

File:Radiation warning symbol.svg|Ionizing radiation hazard trefoil

File:Fallout shelter symbol.svg|Fallout shelter trefoil

File:Biohazard symbol.svg|Biological hazard trefoil

File:Recycle001.svg|Universal recycling symbol

File:Pictogram_VORTAC.svg|VORTAC Aircraft Navigation Beacon

File:WikiProject Scouting trefoil fade.svg|One particular stylized form of the heraldic trefoil is used as the main element in the logo of most Girl Guiding and Girl Scouting organizations. For Girl Scouts, the three trefoil leaves represent the three-fold promise: "To serve God and my country, to help people at all times, and to live by the Girl Scout law."

While the green trefoil is considered by many to be the symbol of Ireland, the harp has much greater officially recognized status. Therefore, shamrocks generally do not appear on Irish coins or postage stamps.

A trefoil is also part of the logo for Adidas Originals, which also includes three stripes.