Ellipticity

Part of speech: noun

Definitions

1. The characteristic of having an ellipsoidal shape points to its geometry and form
2. it describes the extent to which an object's shape diverges from being circular or spherical
3. The measure of how much a shape resembles an ellipse rather than a circle reveals its geometric properties and deviations

Etymology: Ellipticity is a plain English compound: "elliptic" with the suffix "-ity," which turns an adjective into a noun meaning "the quality of being" that adjective. The adjective "elliptic" came into English from Late Latin "ellipticus," and that in turn traces back to Ancient Greek "elleiptikos," from "elleipein," "to fall short" or "to leave out." The Greek verb is itself built from "en-," "in," and "leipein," "to leave," so the idea behind the shape is one of something left lacking. The Greek sense of "falling short" is the key to the geometry. A circle is the ideal case of a conic section, and an ellipse is what you get when a plane cuts a cone at an angle that is steeper than the cone's side but not vertical. Ellipticity is the measure of how far a shape departs from being a perfect circle, so the word carries the older "deficiency" meaning into a precise mathematical and astronomical idea.

Synonyms: ovalness, elliptical shape

Antonyms: circularity