The phrase "pyramid of the tympanum" refers to a specific architectural feature commonly found in ancient structures, particularly in temples and churches. A synonym for this phrase could be "tympanum pinnacle" or "tympanum apex". This term describes the highest point or peak of the tympanum, which is the triangular or arched space above a doorway. It often served as a decorative element, showcasing intricate carvings or sculptures. Another possible synonym could be "tympanum summit", emphasizing the idea of the highest point or summit of this architectural feature. These synonyms help to convey the notion of the pinnacle or topmost area of the tympanum within architectural discussions.