Other forms: halos
A halo is a ring of light seen around the sun or moon through thin cloud. A halo round the moon, a 22-degree halo, a solar halo.
It is made by ice crystals in high cirrus cloud bending the light, and the commonest one sits at twenty-two degrees from the sun because of the shape of the crystals. A halo round the moon is a genuine sign of rain, since cirrus often runs ahead of a warm front. In art, a halo is the disc of light round a saint's head. Note the halo effect, where one good quality colours judgement of everything else.
1nounhaloA ring of light around the sun or moon.
“The halo sits about twenty-two degrees out.”
2noundiscThe disc of light round a saint's head in art.
“In the old painting, the saint has a golden halo around her head.”
halo is a ring of light.
Greek halos meant a threshing floor, and then a disc — the oxen walked in a circle, and the circle gave the word its shape. English took it in 1563.
Ancient Greek
ἅλως — threshing floor; disk; disk of the sun or moon; ring of light around the sun or moon
Latin
halōs
English, today
halo
From Latin halōs, from Ancient Greek ἅλως (“threshing floor; disk; disk of the sun or moon; ring of light around the sun or moon”), of unknown origin. The threshing floor's circular threshold or oxen walking on it in a circle gave rise to the other meanings. Used in English since 1563; the sense of light around someone’s head since 1646.
Etymology from Wiktionary, CC BY-SA
Practised in Weather & Seasons, Light & Shadow, Shapes & Lines