Source : Webster's Revised Unabridged Dictionary (1913)

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.

Quadric \Quad"ric\, a. (Math.)
   Of or pertaining to the second degree.

Source : WordNet®

quadric
     n : a curve or surface whose equation (in Cartesian coordinates)
         is of the second degree [syn: {quadric surface}]