- (n.) The great circle of the celestial sphere, coincident with the plane of the earth's equator; -- so called because when the sun is in it, the days and nights are of equal length; hence called also the equinoctial, and on maps, globes, etc., the equinoctial line.
- (n.) The imaginary great circle on the earth's surface, everywhere equally distant from the two poles, and dividing the earth's surface into two hemispheres.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). equator. Retrieved September 20, 2026, from http://smartdefine.org/equator/definitions/2004385 |
| Chicago | Webster's. 2011. "equator" http://smartdefine.org/equator/definitions/2004385 (accessed September 20, 2026). |
| Harvard | Webster's 2011, equator, Smart Define, viewed 20 September, 2026, <http://smartdefine.org/equator/definitions/2004385>. |
| MLA | Webster's. "equator" 27 May 2011. Web. 20 September 2026. <http://smartdefine.org/equator/definitions/2004385> |