Category:Equator

E*qua"tor, n. Etym: [L. aequator one who equalizes: cf. F. équateur equator. See Equate.]

1. (Geog.)

Defn: 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.

2. (Astron.)

Defn: 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. Equator of the sun or of a planet (Astron.), the great circle whose plane passes through through the center of the body, and is perpendicular to its axis of revolution. -- Magnetic equator. See Aclinic.