Webster's Revised Unabridged Dictionary · 1913

Paraboloid

Paraboloid (-loid) , noun

[Parabola + -oid: compare French paraboloide.]

(Geometry) The solid generated by the rotation of a parabola about its axis; any surface of the second order whose sections by planes parallel to a given line are parabolas.

The term paraboloid has sometimes been applied also to the parabolas of the higher orders.