http://i.ytimg.com/vi/8pdYzOOFEKc/maxresdefault.jpg

Voussoirs are the wedge-shaped stones forming an arch. The arch itself can be either curved or pointed.



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Note added at 1 day 4 hrs (2024-02-04 06:18:31 GMT)
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You could omit "voussoirs forming" to avoid repetition of "voussoirs".

Unfortunately, we only know that these ornaments date from the Ottoman period and were used in Arabia, but not exactly what they look like. Apparently Ruth is not aware of this either. So we can only try to offer generic terms that cover a variety of different designs. On the other hand, such patterns were and are known worldwide from all periods, so we are not limited to Arabia and the period from the 14th to the 19th century.

A meander or meandros (Greek: Μαίανδρος) is a decorative border constructed from a continuous line, shaped into a repeated motif. Among some Italians, these patterns are known as "Greek Lines". Such a design may also be called the Greek fret or Greek key design, although these terms are modern designations even though the decorative motif appears thousands of years before that culture, thousands of miles away from Greece, and among cultures that are continents away from it.
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Byzantine meander on the south-west door, unknown architect or sculptor, 829-842, bronze, Hagia Sophia, Istanbul, Turkey
https://en.wikipedia.org/wiki/Meander_(art)

Key pattern is the generic term for an interlocking geometric motif made from straight lines or bars that intersect to form rectilinear spiral shapes
https://en.wikipedia.org/wiki/Key_pattern

The parties of triangles can be rectilinear and curvilinear.
Les parties des triangles peuvent être rectiligne et curviligne.
https://context.reverso.net/übersetzung/englisch-franzosisch...

An overview of the decoration elements from the first two layers in Pod reveals a relatively modest spectrum of linear, incised motifs, such as simple or double zigzag lines, both horizontal and vertical (Fig. 3/22-23), rows of bigger or smaller chevrons (Fig. 3/34), ladder-like bands (Fig. 3/35-36) and hatched triangles ( Fig. 3/38-43). Among the curvilinear ornaments are crescents (Figs. 3/25, 28; 4/24, 27), opposed bow lines (Fig. 3/48) and circles (Fig. 3/45),
https://www.researchgate.net/figure/Pottery-and-incised-orna...

… includes both rectilinear and complex curvilinear motifs, often in conjunction with each other. The simplest rectilinear-geometric pattern consists of stripes (simple or covered vertically or inclined lines), rhombuses, squares, rectangles,triangles, zigzags, inscribed triangles, light and dark squares arrange in a checkerboard order, hexagons, diagonally crossed squares and rectangles, crosses made up of rhombs, grids and the like. Curvilinear ornaments include lyroid patters, various types of spirals (single, paired and S-shaped), horn-shaped figures, crosses (branched at the ends or having rhomboid thickening on them), “wave”, a figure similar to the heart, with a diamond or cross at the top, an arc, arcs with crosses at the junction, palmettos, almond-shaped figures, four-petal rosettes and a circulating pattern.
https://m.vk.com/wall-21242429_215096?lang=en

His blending of Grecian columns with spiral and curvilinear ornaments blends the emphasis on proportion with an updated sense of movement.
https://gohighbrow.com/classicism/

Chalcolithic pottery with bold curvilinear ornaments in fantastic style owes its origins to the meandroid patterns of the C.H seals.
https://www.catalhoyuk.com/archive_reports/1997/ar97_18.html

The selamlık kiosk is remarkable with its carved wooden eaves, curvilinear ornaments and wooden adornment elements. Inside, the main space is densely adorned with vegetative ornaments and other recurrent decorative motives.
https://pdf.sciencedirectassets.com/277811/1-s2.0-S187704281...

The Vienna Secessionists used geometric and natural forms, free curvilinear ornaments as well as abstract representations with artistic freedom.
https://www.osmanlimirasi.net/dergi/emergence-of-the-istanbu...