ellipse

noun

1. a closed plane curve resulting from the intersection of a circular cone and a plane cutting completely through it

   noun.shape

   Examples

   The sums of the distances from the foci to any point on an ellipse is constant.

   Synonyms oval

   Source: WordNet 3.0

2. An oval or oblong figure, bounded by a regular curve, which corresponds to an oblique projection of a circle, or an oblique section of a cone through its opposite sides. The greatest diameter of the ellipse is the major axis, and the least diameter is the minor axis. See <i>Conic section</i>, under <u>Conic</u>, and cf. <u>Focus</u>.

   noun

   Source: webster1913