Airglow, a term used to describe the faint luminosity of the Earth's upper atmosphere, has several synonyms that can be used to describe this phenomenon. One such term is noctilucent clouds, which are high-altitude clouds that reflect sunlight during the night and create a glowing effect. Another synonym for airglow is polar light, which is caused by the interaction of charged particles from the sun with the Earth's magnetic field. This phenomenon creates colorful, dancing lights that can be seen in the polar regions. Aurora borealis, or the Northern Lights, is another synonym for airglow that is well known for its breathtaking displays of light. Finally, the term phosphorescence could also be used to describe airglow, as it refers to the emission of light from a substance after it has been exposed to radiation.