- a closed conic section shaped like a flattened circle and formed by an inclined plane that does not cut the base of the cone. Standard equation x2/a2 + y2/b2 = 1, where 2a and 2b are the lengths of the major and minor axes. Area: πab
WordReference Random House Learner's Dictionary of American English © 2026
el•lipse /ɪˈlɪps/USA pronunciation
n. [countable]
WordReference Random House Unabridged Dictionary of American English © 2026- Mathematicsa plane curve figure shaped like a flattened circle or oval.
el•lipse
(i lips′),USA pronunciation n. [Geom.]
- Mathematicsa plane curve such that the sums of the distances of each point in its periphery from two fixed points, the foci, are equal. It is a conic section formed by the intersection of a right circular cone by a plane that cuts the axis and the surface of the cone. Typical equation: (x2/a2) + (y2/b2) = 1. If a = b the ellipse is a circle. See diag. under conic section.
- Latin ellīpsis ellipsis; or by back formation from the plural ellipses
- French
- 1745–55
Collins Concise English Dictionary © HarperCollins Publishers::
ellipse /ɪˈlɪps/ n
'ellipse' also found in these entries (note: many are not synonyms or translations):
cone
- conics
- conic section
- conoid
- ellipsoid of revolution
- elliptical
- galaxy
- Kepler's laws
- minor axis
- oval
- ovolo
- trammel
- ellipsograph
- ellipsoid
- ellipsometer
- elliptically
- ellipticity
- fanlight
- focus
- latus rectum
- major axis
- oblate
- parallactic ellipse
- parallax
- prolate
- semiellipse
- semimajor axis
- semiminor axis
