A closed curve, the locus of a point such that the sum of the distances from that point to two other fixed points (called the foci of the ellipse) is constant; equivalently, the conic section that is the intersection of a cone with a plane that does not intersect the base of the cone.
"The architect used an ellipse as the mathematical model for designing the curved ceiling of the concert hall."
To remove from a phrase a word which is grammatically needed, but which is clearly understood without having to be stated.
"In her speech about budget cuts, she dropped the words that were already obvious because everyone knew exactly what was being saved."
A park in Washington, District of Columbia, United States
"We spent our Sunday afternoon strolling through the National Mall to visit the iconic green space known as the Ellipse."