noun1. the great circle of the earth with a latitude of 0°, lying equidistant from the poles; dividing the N and S hemispheres
2. a circle dividing a sphere or other surface into two equal symmetrical parts
3. magnetic equator
4. astronomy celestial equator
Word origin
C14: from Medieval Latin (
circulus)
aequātor (
diei et noctis) (circle) that equalizes (the day and night), from Latin
aequāre to make
equal