GLOSSARY OF TECHNICAL WORDS. Abacus.—The upper portion of the capital of a column, upon which the weight to be carried rests. Aisle (Lat. ala).—The side subdivision in a church; occasionally all the subdivisions, including the nave, are called aisles. Apse.—A semicircular or polygonal termination to, or projection from, a church or other public building. Arcade.—A range of arches, supported on piers or columns.... more...