The Collaborative International Dictionary of English v.0.48:

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.
      [1913 Webster]

   2. (Geom.) A line described according to some low, and having
      no finite portion of it a straight line.
      [1913 Webster]

   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.
      [1913 Webster]