Definify.com

Webster 1913 Edition

Equator

E-qua′tor

,
Noun.
[L.
aequator
one who equalizes: cf. F.
équateur
equator. See
Equate
.]
1.
(Geog.)
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.)
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
Equator 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
.

Webster 1828 Edition

Equator

EQUA'TOR

,
Noun.
[L. from oequo, to make equal.] In astronomy and geography, a great circle of the sphere, equally distant from the two poles of the world, or having the same poles as the world. It is called equator, because when the sun is in it, the days and nights are of equal length; hence it is called also the equinoctial, and when drawn on maps, globes and planispheres, it is called the equinoctial line, or simply the line. Every point in the equator is 90 degrees or a quadrant's distance from the poles; hence it divides the globe or sphere into two equal hemispheres, the northern and southern. At the meridian, the equator rises as much above the horizon as is the complement of the latitude of the place.

Similar Results