Pronunciation: (pär-hē'lē-un, -hēl'yun),[key] —n., —pl.-he•li•aPronunciation: (-hē'lē-u, -hēl'yu).[key]Meteorol. a bright circular spot on a solar halo; a mock sun: usually one of two or more such spots seen on opposite sides of the sun, and often accompanied by additional luminous arcs and bands. Also called sundog. Cf. paraselene.