Meaning of precession of the equinoxes

preces'sion of the e'quinoxes

Pronunciation: [key]
  1. the earlier occurrence of the equinoxes in each successive sidereal year because of the slow retrograde motion of the equinoctial points along the ecliptic, caused by the precession of the earth's axis of rotation; a complete precession of the equinoxes requires about 25,800 years.
  2. the resulting drift of celestial coordinates with respect to the positions of celestial objects.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.