late 14c., from Medieval Latin aequator (diei et noctis) "equalizer (of day and night)," agent noun from Latin aequare "make equal" (see equate). When the sun is on the celestial equator, twice annually, day and night are of equal length. Sense of "celestial equator" is earliest, extension to "terrestrial line midway between the poles" first recorded in English 1610s.
例文
1. GPS operates best near the equator .
全地球測位システムは赤道付近で最も性能が良い。
2.The equator is an imaginary line around the midddle of the earth.
赤道は地球の腰を囲む仮想的な線である。dd>
3.Singapore is near the equator .
シンガポールは赤道付近に位置している。dd>
4.The United States is north of the equator .
米国は赤道の北に位置している。
5.All the planets orbit the Sun in roughly the same plane,round its equator .