paraboloid
- n a surface having parabolic sections parallel to a single coordinate axis and elliptic sections perpendicular to that axis
- When three years of grinding (done slowly to avoid distortion caused by frictional heat) and cleaning with blasts of electrons have produced a concave paraboloid surface true to .
- He also flattened the outer curves of the lenses from spherical to paraboloid shapes.
- Now the big glass disc, yellowish blue and slightly murky like an old Pyrex dish, is a paraboloid perfect within two millionths of an inch.