n. The state of being round, or circular, spherical, globular, cylindrical, curved, or convex; circularity; sphericity; cylindrical form; rotundity; convexity: as, the roundness of the globe, of the orb of the sun, of a ball, of a bowl, of a hill, etc.n. The quality of being well filled or rounded out metaphorically; fullness, completeness, openness, positiveness, boldness, or the like.n. Synonyms Roundness, Rotundity, plumpness, globularity. Roundness applies with equal freedom to a circle, a sphere, a cylinder, or a cone, and, by extension, to forms that by approach suggest any one of these: as, roundness of limb or cheek. Rotundity now applies usually to spheres and to forms suggesting a sphere or a hemisphere: as, the rotundity of the earth or of a barrel; rotundity of abdomen.