Curve Curve, n. [See Curve, a., Cirb.] 1. A bending without angles; that which is bent; a flexure; as, a curve in a railway or canal. 2. (Geom.) A line described according to some low, and having no finite portion of it a straight line. Axis of a curve. See under Axis. Curve of quickest descent. See Brachystochrone. Curve tracing (Math.), the process of determining the shape, location, singular points, and other peculiarities of a curve from its equation. Plane curve (Geom.), a curve such that when a plane passes through three points of the curve, it passes through all the other points of the curve. Any other curve is called a curve of double curvature, or a twisted curve.