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 regular three-dimensional object in which every cross-section is a circle; the figure described by the revolution of a circle about its diameter .
The region in which something or someone is active; one's province, domain.
The set of all points in three-dimensional Euclidean space (or n-dimensional space, in topology) that are a fixed distance from a fixed point .
A spherical physical object; a globe or ball.
Any of the concentric hollow transparent globes formerly believed to rotate around the Earth, and which carried the heavenly bodies; there were originally believed to be eight, and later nine and ten; friction between them was thought to cause a harmonious sound (the music of the spheres).
The extension of a general conception, or the totality of the individuals or species to which it may be applied.
An area of activity for a planet; or by extension, an area of influence for a god, hero etc.
To place in a sphere, or among the spheres; to ensphere.
To make round or spherical; to perfect.