n. 1. The apparent path of the sun among the stars over the course of the year. The ecliptic is the great circle of the celestial sphere which is cut by the plane of the earth's orbit. 2. A great circle inscribed on a terrestrial globe inclined at an approximate angle of 23°26′ to the equator and representing the apparent motion of the sun in relation to the earth during a year. 3. The plane defined by the earth's solar orbit, with the sun at its center, that extends throughout the solar system. [Middle English ecliptik, from Medieval Latin (līnea) eclīptica, ecliptic (line), from Latin eclīpticus, of an eclipse, from Greek ekleiptikos, from ekleipein, to fail to appear; see ECLIPSE.] |
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