a faint spot of light in the night sky that appears directly opposite the position of the sun; a reflection of sunlight by micrometeoric material in space
source: WordNet 3.0
An exceedingly faint roundish or somewhat oblong nebulous light near the ecliptic and opposite the sun, best seen during September and October, when in the constellations Sagittarius and Pisces. Its cause is not yet understood. Called also Gegenschein.
