corona

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A faintly colored luminous ring or halo appearing to surround a celestial body when viewed through a haze or thin cloud, especially such a ring around the moon or sun, caused by scattering or diffraction of light from suspended particulate matter in the intervening medium.
• noun The luminous irregular envelope of extremely hot and highly ionized gas located 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.
• noun Botany A crown-shaped, funnel-shaped, or trumpet-shaped outgrowth or appendage of the perianth of certain flowers, such as a daffodil.
• noun Electricity A faint glow enveloping the high-field electrode in a corona discharge, often accompanied by streamers directed toward the low-field electrode.

from The Century Dictionary.

• noun In zoology, the upper, branched portion of a crinoid, as distinguised from the stem or columna.
• noun See the extract.
• noun A cucullus or hood.
• noun The ring of primary wood in the medullary sheath.
• noun Same as aurora, 5.
• noun A phenomenon seen when an artificial cloud is viewed by transmitted light; an artificial halo.
• noun A crown.
• noun Specifically Among the Romans, a crown or garland bestowed as a reward for distinguished military service.
• noun In architecture, a member of a cornice situated between the bed-molding and the cymatium.
• noun [LL.] Eccles., the horizontal stripe running around a miter at the lower edge, surrounding the head of the wearer. See miter.
• noun [NL.] In zoology and anatomy:
• noun The crown of the head.
• noun The crown of a tooth; the body of a tooth beyond the cingulum.
• noun Some part or organ likened to a crown.
• noun In echinoderms, the body-wall of an echinus, exclusive of the peristome and of the periproct.
• noun In ornithology, the top of the head; the cap or pileum.
• noun The trochal disk of a rotifer.
• noun In sponges, specifically, an irregular spicule, in the form of a ring, bearing rays or spines.
• noun [NL.] In botany: A crown-like appendage on the inner side of a corolla, as in plants of the genus Silene, and in the passionflower, comfrey, and daffodil.
• noun A crown-like appendage at the summit of an organ, as the pappus on the seed of a dandelion.
• noun The ray or circle of ligulate florets surrounding the disk in a composite flower.
• noun A halo; specifically, in astronomy, a halo or luminous circle around one of the heavenly bodies; especially, the portion of the aureola observed during total eclipses of the sun which lies outside the chromosphere, or region of colored prominences.
• noun 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.
• noun Same as corona lucis (which see, below).
• noun In music, an old name for fermata.
• noun the Southern Crown, an ancient southern constellation about the knee of Sagittarius, represented by a garland.
• noun an ancient northern constellation between Hercules and Boötes, represented by a garland with two streamers.
• noun (literally, a crown of light), a chandelier or luster having the lights arranged in a circle, or in several circles whose centers come upon the same vertical axis, suspended from the roof or vaulting of a church and lighted on ceremonial occasions. In the larger and richer examples, however, the general disposition only is circular, this form being broken by lobes, cusps, and the like, along which the lights are arranged. The bounding line is usually marked by a broad band of metal, ornamented with repoussé work, enamel, etc., and having sacred texts inscribed upon it; to this band the separate candlesticks are attached. Also called corona.

from the GNU version of the Collaborative International Dictionary of English.

• noun A crown or garland bestowed among the Romans as a reward for distinguished services.
• noun (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.
• noun (Anat.) The upper surface of some part, as of a tooth or the skull; a crown.
• noun (Zoöl.) The shelly skeleton of a sea urchin.
• noun (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.
• noun An inner appendage to a petal or a corolla, often forming a special cup, as in the daffodil and jonquil.
• noun Any crownlike appendage at the top of an organ.
• noun A circle, usually colored, seen in peculiar states of the atmosphere around and close to a luminous body, as the sun or moon.
• noun 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.
• noun 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.
• noun (Mus.) A character [�] called the pause or hold.