楕だ円えん体たい

noun

ellipsoid

A three-dimensional shape whose plane sections are ellipses or circles; used in geometry and related fields.

• 地ち球きゅうは完かん全ぜんな球きゅうではなく、楕だ円えん体たいに近ちかい形かたちをしている。

  The Earth is not a perfect sphere but is shaped more like an ellipsoid.