The Collaborative International Dictionary of English v.0.48:
Corona \Co*ro"na\ (k?-r?"n?), n.; pl. L. Coron[ae] (-n?), E.
Coronas (-n?z). [L. corona crown. See Crown.]
1. A crown or garland bestowed among the Romans as a reward
for distinguished services.
2. (Arch.) The projecting part of a Classic cornice, the
under side of which is cut with a recess or channel so as
to form a drip. See Illust. of Column.
3. (Anat.) The upper surface of some part, as of a tooth or
the skull; a crown.
4. (Zool.) The shelly skeleton of a sea urchin.
5. (Astronomy) A peculiar luminous appearance, or aureola,
which surrounds the sun, and which is seen only when the
sun is totally eclipsed by the moon.
(a) An inner appendage to a petal or a corolla, often
forming a special cup, as in the daffodil and jonquil.
(b) Any crownlike appendage at the top of an organ.
(a) A circle, usually colored, seen in peculiar states of
the atmosphere around and close to a luminous body, as
the sun or moon.
(b) A peculiar phase of the aurora borealis, formed by
the concentration or convergence of luminous beams
around the point in the heavens indicated by the
direction of the dipping needle.
8. A crown or circlet suspended from the roof or vaulting of
churches, to hold tapers lighted on solemn occasions. It
is sometimes formed of double or triple circlets, arranged
pyramidically. Called also corona lucis. --Fairholt.
9. (Mus.) A character [[pause]] called the pause or hold.