EQUATOR

noun Etymology: Middle English, from Medieval Latin a~, literally, equalizer, from Latin aequare Date: 14th century the great circle of the celestial sphere whose plane is perpendicular to the axis of the earth, a great circle of the earth or a celestial body that is everywhere equally distant from the two poles and divides the surface into the northern and southern hemispheres, 3. a circle or circular band dividing the surface of a body into two usually equal and symmetrical parts, ~ial plane , great circle