1 Astronomy the rarefied gaseous envelope of the sun and other stars. The sun’s corona is normally visible only during a total solar eclipse, when it is seen as an irregularly shaped pearly glow surrounding the darkened disc of the moon.
(also corona discharge) Physics the glow around a conductor at high potential.
a small circle of light seen round the sun or moon, due to diffraction by water droplets.
2 Anatomy a crown or crown-like structure.
3 Botany the cup-shaped or trumpet-shaped outgrowth at the centre of a daffodil or narcissus flower.
4a circular chandelier in a church.
5 Architecture a part of a cornice having a broad vertical face.
