A surface, all of whose cross sections are elliptic or circular (including the sphere), that generalises the ellipse and in Cartesian coordinates (x, y, z) is a quadric with equation x²/a² + y²/b² + z²/c² = 1.
Such a surface used as a model of the shape of the earth.
Shaped like an ellipse; elliptical.
Having the tridimensional shape of an ellipse rotated on its long axis.
Of or pertaining to an ellipse; elliptic.
A curve on the surface of a cylinder or cone such that its angle to a plane perpendicular to the axis is constant; the three-dimensional curve seen in a screw or a spiral staircase.
A small volute under the abacus of a Corinthian capital.
The incurved rim of the external ear.
An upside down midair 360° spin in playboating.
To form or cause to form a helix.