Ellipse

[Sarah]

An oval or oblong figure, bounded by a regular curve, whichcorresponds to an oblique projection of a circle, or an obliquesection of a cone through its opposite sides. The greatest diameterof the ellipse is the major axis, and the least diameter is the minoraxis. See Conic section, under Conic, and cf. Focus.

[Kai]

A regular oval shape, traced by a point moving in a plane so that the sum of its distances from two other points (the foci) is constant, or resulting when a cone is cut by an oblique plane which does not intersect the base.