大たい圏けん

noun

great circle

A geometric term for the largest possible circle on a sphere, such as the equator or a meridian. Used in navigation and spherical geometry.

• 大たい圏けん航こう路ろは最さい短たん距きょ離りを結むすぶ。

  A great-circle route connects the shortest distance.

• 赤せき道どうは地ち球きゅうの大たい圏けんの一ひとつだ。

  The equator is one of the Earth's great circles.