1. the apparent path of the sun among the stars during the year
Usage: astronomy
2. the great circle on the celestial sphere that is the intersection of the plane of the earth’s orbit with the celestial sphere
Usage: astronomy; technical

1. of or relating to the ecliptic or an eclipse
Usage: astronomy

Examples

• The ecliptic is tilted at about 23.5 degrees to the celestial equator.
• Planets in our solar system orbit close to the ecliptic plane.
• The zodiac constellations lie along the ecliptic.
• Astronomers use the ecliptic as a reference for celestial coordinates.
• The moon’s orbit is inclined about 5 degrees to the ecliptic.
• Solar eclipses occur when the moon crosses the ecliptic plane.
• The ecliptic coordinate system is useful for tracking planetary motion.