English to English
- the property possessed by a round shape that is flattened at the poles
The oblateness of the planet.
source: WordNet 3.0
- 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 &frac1x29966;.
source: Webster 1913