quadric n 1: a curve or surface whose equation (in Cartesian coordinates) is of the second degree [syn: {quadric}, {quadric surface}]
Quadric \Quad"ric\, a. (Math.) Of or pertaining to the second degree. [1913 Webster]
Quadric \Quad"ric\, n. (a) (Alg.) A quantic of the second degree. See {Quantic}. (b) (Geom.) A surface whose equation in three variables is of the second degree. Spheres, spheroids, ellipsoids, paraboloids, hyperboloids, also cones and cylinders with circular bases, are quadrics. [1913 Webster]