The word "cornice" entered English in the 1560s from Italian cornice, meaning a ledge, frame, or moulding. The Italian word's deeper etymology is debated. The most widely accepted derivation traces it to Greek korōnis (a curved line, a hook, a flourish at the end of a book), from korōnē (something curved, and also the word for crow — because of the bird's curved beak). An alternative theory connects it to Latin cornix (crow), which would lead to the same Greek source. In either case, the core concept is curvature or projection.
In classical architecture, the cornice is the uppermost element of the entablature — the horizontal structure that rests on top of columns. The entablature comprises three parts from bottom to top: the architrave, the frieze, and the cornice. The cornice projects outward from the building face, creating a shadow line and deflecting rainwater away from the wall below. This practical function — protecting the wall from water damage — explains why cornices appear on buildings across virtually every architectural tradition, not only the Greco-Roman one.
The three classical orders — Doric, Ionic, and Corinthian — each prescribed specific cornice profiles. The Doric cornice featured mutules (flat projecting blocks), the Ionic had dentils (small tooth-like blocks), and the Corinthian combined both with elaborate carved decoration. Renaissance architects, particularly Alberti and Palladio, codified these distinctions and established the cornice as an essential element of properly proportioned design.
Beyond architecture, "cornice" has a specialized meaning in mountaineering: an overhanging mass of wind-compacted snow that forms on the leeward side of a ridge. These cornices can extend several metres beyond the actual rock edge, creating a dangerous trap for unwary climbers who may step onto what appears to be solid ground but is actually unsupported snow. Cornice collapses are a significant cause of avalanches and climbing accidents. The architectural metaphor is apt
The French form corniche entered English separately as a term for a road built along a cliff face, most famously the three corniche roads between Nice and Monaco on the Côte d'Azur. These roads, built at different elevations on the steep coastal cliffs, take their name from the ledge-like appearance of the road as seen from below — a narrow horizontal projection on a vertical face, precisely like an architectural cornice.
In interior design, cornices refer to decorative mouldings at the junction of wall and ceiling, also known as "crown moulding" in American English. The word thus spans scales from the monumental (temple entablatures) to the domestic (plaster ceiling trim) to the natural (snow formations on mountain ridges), unified by the concept of a horizontal projection from a vertical surface.