1) Bulginess 2) Ellipticity 3) Roundedness 1) Ellipticity 
• (n.) The quality or state of being oblate.
The measure of how much a rotating object deviates from being a perfect sphere. A perfect sphere would have an oblateness of 0.0 (0%). The Earth for example is oblate to a factor of 0.0034 (0.34%), while Saturn, the most oblate of the planets has a figure of 0.108 (10.8%). Generally, the planets have an equatorial bulge and in the case of Saturn, i...
Ob·late'ness noun The quality or state of being oblate. 
A measure of flattening at the poles of a planet or other celestial body.
[n] - the property possessed by a rounded shape that is flattened at the poles
ellipticity noun the property possessed by a round shape that is flattened at the poles; `the oblateness of the planet`