n. 椭圆, 椭圆形

[计] 椭圆

[ noun ]
a closed plane curve resulting from the intersection of a circular cone and a plane cutting completely through it
<noun.shape>
the sums of the distances from the foci to any point on an ellipse is constant

Ellipse \El*lipse"\ ([e^]l*l[i^]ps"), n. [Gr. 'e`lleipsis,
prop., a defect, the inclination of the ellipse to the base
of the cone being in defect when compared with that of the
side to the base: cf. F. ellipse. See {Ellipsis}.]
1. (Geom.) 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 {Conic section}, under {Conic}, and cf. {Focus}.

2. (Gram.) Omission. See {Ellipsis}.

3. The elliptical orbit of a planet.

The Sun flies forward to his brother Sun;
The dark Earth follows wheeled in her ellipse.
--Tennyson.