A tympanum is the semi-circular or triangular decorative wall surface over an entrance, door or window, which is bounded by a lintel and an arch. It often contains pedimental sculpture or other imager
The late Romanesque tympanum of Vézelay Abbey, Burgundy, France, 1130s
Rose window on St. Stephen's Cathedral - Vienna
Tympanum of the Abbey of Sainte-Foy in Conques
Tympanum on the Santiago de Compostela cathedral - Spain
A lunette is a crescent- or half-moon–shaped or semicircular architectural space or feature, variously filled with sculpture, painted, glazed, filled with recessed masonry, or void. A lunette may also
Tympanum (architecture)
…carved, central figures of Christ and an important contemporary person to remind people of the importance of these figures as they enter the church. Lunette: semi-circular tympanum Church architecture…
Lunette over the main door of the Luxembourg Palace in Paris
Charles Sprague Pearce, Rest (1896). Mural in a lunette in the Thomas Jefferson Building of the Library of Congress, Washington, D.C.