The dark circle within the cone is an ellipse.

The definition of an ellipse is a path taken or a shape that results when a flat plane intersects a cone in a direction which is not parallel to the base of the cone.

An example of an ellipse are the rings of Saturn.

## ellipse

noun

*pl.*-·lip′ses·

Geom. the path of a point that moves so that the sum of its distances from two fixed points, the foci, is constant; closed curve formed by the section of a cone cut by a plane less steeply inclined than the side of the cone

Origin of ellipse

Modern Latin*ellipsis*from Classical Greek

*elleipsis*, a defect, ellipse from

*elleipein*, to fall short from

*en-*, in +

*leipein*, to leave (see loan): so named from falling short of a perfect circle

## ellipse

noun

- A plane curve, especially:
**a.**A conic section whose plane is not parallel to the axis, base, or generatrix of the intersected cone.**b.**The locus of points for which the sum of the distances from each point to two fixed points is equal. - Ellipsis.

Origin of ellipse

French*from*Latin

*ellīpsis*

*from*Greek

*elleipsis*

*a falling short, ellipse*

*from*

*elleipein*

*to fall short (from the relationship between the line joining the vertices of a conic and the line through the focus and parallel to the directrix of a conic)*

*en-*

*in*; see

**en-**

^{2}.

*leipein*

*to leave*; see

*leik*in Indo-European roots.

^{w}-## ellipse

Noun

(*plural* ellipses)

Verb

(*third-person singular simple present* ellipses, *present participle* ellipsing, *simple past and past participle* ellipsed)

Origin

From French *ellipse*.