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

  • noun 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 −38.83°C; boiling point 356.62°C; specific gravity 13.546 (at 20°C); valence 1, 2. cross-reference: Periodic Table.
  • noun Temperature.
  • noun Any of several weedy plants of the genera Mercurialis and Acalypha.

from The Century Dictionary.

  • noun In Roman mythology, the name of a Roman divinity, who became identified with the Greek Hermes.
  • noun [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.
  • noun Hence [lowercase or cap.] A common name for a newspaper or periodical publication; formerly, also, a newspaper-carrier or a seller of newspapers.
  • noun [lowercase] Warmth or liveliness of temperament; spirit; sprightly qualities; hence, liability to change; fickleness.
  • noun The innermost planet of the solar system.
  • noun [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.
  • noun [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.
  • noun In older usage, the Chenopodium Bonus-Henricus. See allgood and good-King-Henry. This is the English, false, or wild mercury.
  • noun In heraldry, the tincture purple, when blazoning is done by the planets.
  • To wash with a preparation of mercury.

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

  • noun (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.
  • noun (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, ☿.
  • noun (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.
  • noun A carrier of tidings; a newsboy; a messenger; hence, also, a newspaper.
  • noun obsolete Sprightly or mercurial quality; spirit; mutability; fickleness.
  • noun (Bot.) A plant (Mercurialis annua), of the Spurge family, the leaves of which are sometimes used for spinach, in Europe.
  • noun (Bot.) Mercurialis perennis, a perennial plant differing from Mercurialis annua by having the leaves sessile.
  • noun (Bot.) a kind of goosefoot formerly used as a pot herb; -- called Good King Henry.
  • noun (Min.) a mineral chloride of mercury, having a semitranslucent, hornlike appearance.
  • transitive verb obsolete To wash with a preparation of mercury.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun A metal.
  • noun A plant.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

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


from The American Heritage® Dictionary of the English Language, 4th Edition

[Middle English mercurie, from Medieval Latin mercurius, from Latin Mercurius, Mercury.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Mercury.


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  • Hg.

    December 16, 2007

  • It builds up and damages the kidneys and the brain. If you've been poisoned pretty badly, you go insane, your skin becomes yellow and your teeth fall out of their black gums.

    August 18, 2009

  • "8. In older usage, the Chenopodium Bonus-Henricus. See allgood and good-King-Henry. This is the English, false, or wild mercury." --Cent. Dict.

    September 13, 2011

  • There are three forms of mercury which are extremely dangerous.

    1. Elemental mercury. Found in glass thermometers. It’s not harmful if touched, but lethal if inhaled.

    2. Inorganic mercury. Used to make batteries. It is deadly only when ingested.

    3. Organic mercury. Found in fish, such as tuna and swordfish. Consumption should be limited to 170g per week, but can be potentially deadly over long periods of time.

    A famous death caused by mercury is that of Amadeus Mozart, who was given mercury pills to treat his syphilis.

    February 27, 2015