回かい転てん楕だ円えん体たい

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Meanings

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noun

spheroid

A mathematical term for a quadric surface obtained by rotating an ellipse about one of its principal axes; used in geometry, physics, and geodesy.

地ち球きゅうは完かん全ぜんな球きゅうではなく、回かい転てん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 has a shape close to a spheroid.

回-times, round, game

転revolve, turn around, change

楕ellipse

円circle, yen, round

体body, substance, object

Similar words

楕だ円えん体たい
楕円体 is a general ellipsoid, while 回転楕円体 specifically refers to a spheroid formed by rotating an ellipse.
球きゅう体たい
球体 is a sphere; 回転楕円体 is a more specific shape that is flattened or elongated along one axis.

Etymology

Compound of 回転 (rotation) + 楕円体 (ellipsoid), literally 'rotational ellipsoid'. The term is a direct calque from English 'spheroid' or German 'Rotationsellipsoid'.