GHIERA. – Molding that outlines the extrados of the arch. It is used especially in pre-Romanesque and Romanesque architecture, to which it contributes a sense of gravity and solidity.
In S. Pietro di Tuscania (11th century), it is adorned with strange denticulations; in a simpler form it is found in S. Elia di Nepi, and subsequently in a great many Romanesque churches (S. Zeno di Verona, S. Maria di Castello in Genoa, etc.), as well as in some from the beginnings of the Gothic period (S. Galgano). The double g. is characteristic of Pisan and Apulian Romanesque architecture. Mario Zocca