corona

(天)コロナ、光環

(noun) Astronomy A faintly colored luminous ring appearing to surround a celestial body visible through a haze or thin cloud, especially such a ring around the moon or sun, caused by diffraction of light from suspended matter in the intervening medium. Also called aureole.
(noun) Astronomy The luminous irregular envelope of highly ionized gas outside the chromosphere of the sun.
(noun) Architecture The projecting top part of a cornice.
(noun) A cigar with a long tapering body and blunt ends.
(noun) Anatomy The crownlike upper portion of a bodily part or structure, such as the top of the head.

While Willis considers that the term corona was a common one for an apse at the end of a church, citing "Ducange's Glossary," which defines "Corona Ecclesiæ" as