equator
n. countablen. the imaginary line that goes around the middle of the Earth. It is exactly halfway between the North Pole and the South Pole.
n. the imaginary great circle around the Earth's surface, equidistant from the poles and perpendicular to the Earth's axis of rotation. It divides the planet into the Northern and Southern Hemispheres.
Countries near the equator are usually very hot.
The equator passes through several countries, including Ecuador, Kenya, and Indonesia, where the climate is tropical year-round.
Because the Earth is not a perfect sphere, the centrifugal force of its rotation causes a slight bulge at the equator, making the planet an oblate spheroid.
From Late Latin (circulus) aequator (diei et noctis).
Usually used with the definite article 'the'.