ecliptic /ɪˈklɪp.tɪk/noun 3adjective 1forms 1 noun3 •The great circle on the celestial sphere that is the mean apparent path of the sun as viewed from the earth. •A great circle drawn on a terrestrial globe, used for illustrating and solving astronomical problems. •The plane in which this great circle lies. adjective1 •Relating to an eclipse or the ecliptic. formsecliptics