Final answer:
The cymatium is the crowning member of a classical cornice, typically fashioned as a cyma recta, and is part of the entablature in classical architecture.
Step-by-step explanation:
The crowning member of a classical cornice, which is usually a cyma recta, is known as a Cymatium. The classical cornice is part of the entablature, which rests on columns and consists, from top to bottom, of three main parts: the cornice, the frieze, and the architrave. The cornice is the uppermost section, and the cymatium is specifically the ornamental molding that crowns it. In contrast, frieze is the part of the entablature above the architrave that often bears decoration, while architrave is the lowermost component directly above the column capitals. The option 'Cornice Cap' is not a term traditionally used in classical architecture terminology.