mercury

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A silvery-white poisonous metallic element, liquid at room temperature and used in thermometers, barometers, vapor lamps, and batteries and in the preparation of chemical pesticides. Atomic number 80; atomic weight 200.59; melting point -38.87°C; boiling point 356.58°C; specific gravity 13.546 (at 20°C); valence 1, 2. Also called quicksilver. See Table at element.
2. n. Temperature: The mercury had fallen rapidly by morning.
3. n. Any of several weedy plants of the genera Mercurialis or Acalypha.

Century Dictionary and Cyclopedia

1. n. In Roman mythology, the name of a Roman divinity, who became identified with the Greek Hermes. He was the son of Jupiter and Maia, and was the herald and ambassador of Jupiter. As a god of darkness, Mercury is the tutelary deity of thieves and tricksters; he became also the protector of herdsmen, and the god of science, commerce, and the arts and graces of life, and the patron of travelers and athletes. It was he who guided the shades of the dead to their final abiding-place. He is represented in art as a young man, usually wearing a winged hat and the talaria or winged sandals, and bearing the caduceus or pastoral staff and often a purse.
2. n. [lowercase or cap.] Pl. mercuries (-riz). One who acts like the god Mercury in his capacity of a messenger; a conveyor of news or information; an intelligencer.
3. n. Hence [lowercase or cap.] A common name for a newspaper or periodical publication; formerly, also, a newspaper-carrier or a seller of newspapers.
4. n. [lowercase] Warmth or liveliness of temperament; spirit; sprightly qualities; hence, liability to change; fickleness.
5. n. The innermost planet of the solar system. Its mean distance from the sun is 0.387 that of the earth. The inclination (7 degrees) and the eccentricity (0.2056) of its orbit are exceeded only by some of the minor planets. Its diameter is only 3,000 miles, or about of that of the earth; its volume is to that of the earth as 1 to 18.5. It performs its sidereal revolution in 88 days, its synodical in 116. Its proximity to the sun prevents its being often seen with the naked eye. The mass of Mercury, though as yet not very precisely determined, is less than that of any other planet (asteroids excepted). According to Schiaparelli it rotates on its axis in the same way as the moon does, once in each orbital revolution.
6. n. [lowercase] Chemical symbol, Hg; atomic weight, 200.1. A metal of a silver-white color and brilliant metallic luster, unique in that it is fluid at ordinary temperatures. It becomes solid, or freezes, at about—40, and crystallizes in the isornetric system. Its specific gravity at 0 is 13.6; when frozen, according to J. W. Mallet, 14.1932. This metal occurs native, sometimes in considerable quantity; but by far the largest supply is obtained from the sulphid, known as cinnabar. (See cinnabar.) Mercury is not very generally disseminated. In the United States only traces of its ores have been found to the east of the Cordilleras. The principal sources of supply are the mines of Almaden in Spain, of New Almaden and others near the Bay of San Francisco, and of Idria in Austria. Its chief use is in the metallurgic treatment of gold and silver ores by amalgamation. The thermometer and barometer are instruments in which the peculiar qualities of this metal are well illustrated. Commercially the most important salts of mercury are mercurous chlorid (Hg₂Cl₂) or calomel, chiefly used in medicine, and the mercuric chlorid (HgCl₂) or corrosive sublimate, a violent poison used in medicine and extensively in surgery as an antiseptic, and as a preservative in dressing skins, etc., being a very powerful antiseptic. The sulphid (HgS), or cinnabar, when prepared artificially, is called vermilion, and is used as a pigment. The names mercury and quicksilver are entirely synonymous, but the former is rather a scientific designation, and one necessarily used in compound names and in the adjective form; while the latter is a common popular designation of this metal. See amalgam, calomel, quicksilver.
7. n. [lowercase] A plant of the genus Mercurialis, chiefly M. perennis, the dog's-mercury, locally called Kentish balsam (which see, under Kentish), and M. annua, the annual or French mercury. See Mercurialis.
8. n. In older usage, the Chenopodium Bonus-Henricus. See allgood and good-King-Henry. This is the English, false, or wild mercury.
9. n. In heraldry, the tincture purple, when blazoning is done by the planets.
10. To wash with a preparation of mercury.

Wiktionary

1. n. A metal.
2. n. A plant.

GNU Webster's 1913

1. n. (Rom. Myth.) A Latin god of commerce and gain; -- treated by the poets as identical with the Greek Hermes, messenger of the gods, conductor of souls to the lower world, and god of eloquence.
2. n. (Chem.) A metallic element mostly obtained by reduction from cinnabar, one of its ores. It is a heavy, opaque, glistening liquid (commonly called quicksilver), and is used in barometers, thermometers, etc. Specific gravity 13.6. Symbol Hg (Hydrargyrum). Atomic weight 199.8. Mercury has a molecule which consists of only one atom. It was named by the alchemists after the god Mercury, and designated by his symbol, ☿.
3. n. (Astron.) One of the planets of the solar system, being the one nearest the sun, from which its mean distance is about 36,000,000 miles. Its period is 88 days, and its diameter 3,000 miles.
4. n. A carrier of tidings; a newsboy; a messenger; hence, also, a newspaper.
5. n. obsolete Sprightly or mercurial quality; spirit; mutability; fickleness.
6. n. (Bot.) A plant (Mercurialis annua), of the Spurge family, the leaves of which are sometimes used for spinach, in Europe.
7. v. obsolete To wash with a preparation of mercury.

WordNet 3.0

1. n. temperature measured by a mercury thermometer
2. n. (Roman mythology) messenger of Jupiter and god of commerce; counterpart of Greek Hermes
3. n. a heavy silvery toxic univalent and bivalent metallic element; the only metal that is liquid at ordinary temperatures
4. n. the smallest planet and the nearest to the sun