1. Bright spots or halos that appear on either side of the moon, similar to sundogs; a lunar halo phenomenon caused by the refraction of moonlight through ice crystals in the atmosphere.
Usage: plural form; meteorological/astronomical term; also called moon dogs or lunar parhelion

Examples

• On a cold winter night, we observed moondogs glowing on either side of the full moon.
• The moondogs were visible for about an hour before the clouds rolled in.
• Astronomers explained that moondogs form when moonlight refracts through ice crystals high in the atmosphere.
• The bright moondogs made the night sky appear almost as luminous as twilight.
• We photographed the moondogs as they shimmered against the dark sky.