also: うん
Refers to the luminous ring around the sun or moon caused by ice crystals. In everyday speech, かさ is common; うん is a rare literary or technical reading.
There is a halo around the moon tonight.
A large halo was visible around the sun.
lunar halo; moon ring
Standard kanji for atmospheric halos. The reading うん is less common.
Rare on'yomi reading; mainly encountered in compounds or literary contexts.
The kanji 暈 originally meant 'halo' or 'dizziness'. The reading かさ is the native Japanese word for 'halo', while うん is the Sino-Japanese reading. The exact origin of かさ is uncertain.