equator

Etymology

From Late Latin (circulus) aequator (diei et noctis).

noun

1. (geography, often “the Equator”) An imaginary great circle around Earth, equidistant from the two poles, and dividing earth's surface into the northern and southern hemisphere.
   Baishui is about as close to the equator as Tampa, Florida. File:Baishui is about as close to the equator as Tampa, Florida.ogg 2018, VOA Learning English > China's Melting Glacier Brings Visitors, Adds to Climate Concerns
2. (astronomy) A similar great circle on any sphere, especially on a celestial body, or on other reasonably symmetrical three-dimensional body.
3. The midline of any generally spherical object, such as a fruit or vegetable, that has identifiable poles.
   Slice the onion through the equator.
4. The celestial equator.