- (astronomy) A circular band of coloured light, visible around the sun or moon etc., caused by reflection and refraction of light by ice crystals in the atmosphere.
- Anything resembling this band, such as an effect caused by imperfect developing of photographs.
- (religion) nimbus, a luminous disc, often of gold, around or over the heads of saints, etc., in religious paintings.
- The metaphorical aura of glory, veneration or sentiment which surrounds an idealized entity.
- To encircle with a halo.