Found 2 items, similar to equinoctial line.
English → English (WordNet) Definition: equinoctial line equinoctial line n : the great circle on the celestial sphere midway between the celestial poles [syn: celestial equator, equinoctial circle , equinoctial]
English → English (gcide) Definition: equinoctial line Equator \E*qua"tor\, n. [L. aequator one who equalizes: cf. F. ['e]quateur 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. [1913 Webster] 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. [1913 Webster] 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. [1913 Webster]