a circle whose plane is perpendicular to a given plane; (Astronomy) a great circle of the celestial sphere whose plane is perpendicular to the…
the celestial or terrestrial sphere when its equator is perpendicular to the horizon (as it is only at the earth's equator); cf. oblique sphere n. at…
英语词典包含1132095条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。