circle of curvature noun Mathematics. the circle with its center on the normal to the concave side of a curve at a given point on the curve and with its radius equal to the radius of curvature at the point. Liberaldictionary.com What It Really Means to Call Someone "Crude" Can You Translate These Famous Phrases From Emoji? These Are the Longest Words in English These Are the Saddest Phrases in English Also called osculating circle. Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019