1911 Encyclopædia Britannica/Cyma

CYMA (Gr. κῦμα, wave), in architecture, a moulding of double curvature, concave at one end, convex at the other. When the concave part is uppermost, it is called a cyma recta; but if the convex portion is at the top, it is called a cyma reversa. When the crowning moulding of an entablature is of the cyma form, it is called a “cymatium.”