Gegenschein is a rare astronomical phenomenon that refers to a faint elliptical glow that appears opposite the sun in the night sky. While there are no direct synonyms for gegenschein, several related terms can help to describe this unique occurrence. These include zodiacal light, a similar phenomenon caused by sunlight reflecting off cosmic dust in the solar system, and nocturnal light, a general term used to describe any light source visible at night. Additionally, the term "counter glow" is sometimes used to describe gegenschein, as it appears to glow in opposition to the sun's brightness.