回かい転てん楕だ円えん体たいかいてんだえんたいMeanings1nounspheroidA 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