A circular structure having a circular plan and usually the form of a portion of a sphere, so constructed as to exert an equal thrust in all directions. Photo from Florence, Italy, 2018. 2. A squaremetalor fiberglass pan used in forming the ribs of a waffle slab, available in standard 19- and 30-inch (483- and 762-mm) widths and a variety of depths. (Ching, 1995)
