equator
/ɪˈkweɪtə(r)/noun
1- a line notionally drawn on the earth equidistant from the poles, dividing the earth into northern and southern hemispheres and constituting the parallel of latitude 0°（地球的）赤道。
1.1
- a corresponding line on a planet or other body（行星或其他天体的）赤道。
1.2
- Astronomy short for CELESTIAL EQUATOR.【天文】CELESTIAL EQUATOR的简称。
词源
late Middle English: from medieval Latin aequator, in the phrase circulus aequator diei et noctis 'circle equalizing day and night', from Latin aequare 'make equal' （see EQUATE）.