noun noun: halo; plural noun: haloes; plural noun: halos 1. a disk or circle of light shown surrounding or above the head of a saint or holy person to represent their holiness. synonyms: ring of light, nimbus, aureole, glory, crown of light, corona; More the glory associated with an idealized person or thing. "he has long since lost his halo for many ordinary Russians" 2. a circle of white or colored light around the sun, moon, or other luminous body caused by refraction through ice crystals in the atmosphere. synonyms: ring of light, nimbus, aureole, glory, crown of light, corona; More verb verb: halo; 3rd person present: haloes; past tense: haloed; past participle: haloed; gerund or present participle: haloing 1. surround with or as if with a halo.