the property possessed by a round shape that is flattened at the poles
同义词：oblateness
ellipticity详细解释
el.lip.tic.i.ty n.（名词）Deviation from perfect circular or spherical form toward elliptic or ellipsoidal form.椭圆形，椭圆球：从正圆或球形向椭圆或椭圆球的偏离The degree of this deviation.椭圆率：指这种偏离的程度
