In architecture, a lunette (French lunette, "little moon") is a half-moon shaped space, either filled with recessed masonry or void. A lunette is formed when a horizontal cornice transects a round-headed arch

Arch

An arch is a structure that spans a space and supports a load. Arches appeared as early as the 2nd millennium BC in Mesopotamian brick architecture and their systematic use started with the Ancient Romans who were the first to apply the technique to a wide range of structures.-Technical aspects:The...

 at the level of the imposts, where the arch springs. If a door is set within a round-headed arch, the space within the arch above the door, masonry or glass, is a lunette. If the door is a major access, and the lunette above is massive and deeply set, it may be called a tympanum

Tympanum (architecture)

In architecture, a tympanum is the semi-circular or triangular decorative wall surface over an entrance, bounded by a lintel and arch. It often contains sculpture or other imagery or ornaments. Most architectural styles include this element....

.

The term is usefully employed to describe the section of interior wall between the curves of a vault and its springing line. A system of intersecting vaults produces lunettes on the wall surfaces above a cornice. The lunettes in the structure of the Sistine Chapel

Sistine Chapel

Sistine Chapel is the best-known chapel in the Apostolic Palace, the official residence of the Pope in Vatican City. It is famous for its architecture and its decoration that was frescoed throughout by Renaissance artists including Michelangelo, Sandro Botticelli, Pietro Perugino, Pinturicchio...

 inspired Michelangelo

Michelangelo

Michelangelo di Lodovico Buonarroti Simoni , commonly known as Michelangelo, was an Italian Renaissance painter, sculptor, architect, poet, and engineer who exerted an unparalleled influence on the development of Western art...

 to come up with inventive compositions for the spaces.

In neoclassical

Neoclassicism

Neoclassicism is the name given to Western movements in the decorative and visual arts, literature, theatre, music, and architecture that draw inspiration from the "classical" art and culture of Ancient Greece or Ancient Rome...

 architecture of Robert Adam

Robert Adam

Robert Adam was a Scottish neoclassical architect, interior designer and furniture designer. He was the son of William Adam , Scotland's foremost architect of the time, and trained under him...

 and his French contemporaries, like Ange-Jacques Gabriel

Ange-Jacques Gabriel

Ange-Jacques Gabriel was the most prominent French architect of his generation.Born to a Parisian family of architects and initially trained by the royal architect Robert de Cotte and his father , whom he assisted in the creation of the Place Royale at Bordeaux , the younger Gabriel...

, a favorite scheme set a series of windows within shallow blind arches. The lunettes above lent themselves to radiating motifs: a sunburst

Sunburst (design)

A Sunburst is a design or figure commonly used in architectural ornaments and design patterns. It consists of rays or "beams" radiating out from a central disk in the manner of sunbeams. Sometimes part of a sunburst, a semicircular or semi-elliptical shape, is used...

of bellflower husks, radiating fluting, a low vase of flowers, etc.

A lunette may also be segmental, and the arch may be an arc taken from an oval. The spaces are still lunettes.

A lunette is commonly called a half-moon window, when the space is used as a window.