Quadric (?), a. (Math.) Of or pertaining to the second degree.[1913 Webster]
Quadric, 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]