名詞 ellipticity:

1. the property possessed by a round shape that is flattened at the poles
   同義詞：oblateness

el.lip.tic.i.ty

n.（名詞）
Deviation from perfect circular or spherical form toward elliptic or ellipsoidal form.
橢圓形，橢圓球：從正圓或球形向橢圓或橢圓球的偏離
The degree of this deviation.
橢圓率：指這種偏離的程度