ellipticity Meaning, Definition & Usage

  1. noun the property possessed by a round shape that is flattened at the poles
    oblateness.
    • the oblateness of the planet

WordNet

El`lip*tic"i*ty noun
Etymology
Cf. F. ellipticité.
Definitions
  1. Deviation of an ellipse or a spheroid from the form of a circle or a sphere; especially, in reference to the figure of the earth, the difference between the equatorial and polar semidiameters, divided by the equatorial; thus, the ellipticity of the earth is 1⁄29966. ✍ Some writers use ellipticity as the ratio of the difference of the two semiaxes to the minor axis, instead of the major. Nichol.

Webster 1913