quatrefoil

[ kat-er-foil, ka-truh- ]

/ ˈkæt ərˌfɔɪl, ˈkæ trə- /

a leaf composed of four leaflets.

Architecture. a panellike ornament composed of four lobes, divided by cusps, radiating from a common center.

Origin of quatrefoil

1375–1425; Middle English < Middle French quatre four + -foil (as in trefoil)

quat·re·foiled, adjective

The tympana of the choir triforium arches are filled with plate tracery, quatrefoil and cusped.

Cathedral Cities of France |Herbert Marshall
On the south, however, the quatrefoil decoration is slightly different.

Bell's Cathedrals: The Cathedral Church of Carlisle |C. King Eley
This roof has a quatrefoil opening, through which it was possible to see what was taking place in the hall below.

Bell's Cathedrals: The Abbey Church of Tewkesbury |H. J. L. J. Mass
A serpent is under the feet of the Madonna, who is sitting on a throne; angels censing are on either side without the quatrefoil.

Bell's Cathedrals: The Cathedral Church of Wells |Percy Dearmer

The clerestory windows on each side are two-lighted, with quatrefoil heads.

Bell's Cathedrals: The Cathedral Church of Rochester |G. H. Palmer

quatrefoil

/ (ˈkætrəˌfɔɪl) /

a leaf composed of four leaflets

architect a carved ornament having four foils arranged about a common centre, esp one used in tracery

C15: from Old French, from quatre four + -foil leaflet; compare trefoil