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noun mer·cu·ry \ˈmər-kyə-rē, -k(ə-)rē\

Simple Definition of mercury

  • : a silver metal that is liquid at normal temperatures

  • : the mercury in a thermometer that shows the air's temperature

  • Mercury : the planet that is closest to the sun

Source: Merriam-Webster's Learner's Dictionary

Full Definition of mercury

plural mercuries

  1. 1 a capitalized :  a Roman god of commerce, eloquence, travel, cunning, and theft who serves as messenger to the other gods — compare hermes b often capitalized archaic :  a bearer of messages or news or a conductor of travelers

  2. 2 [Middle English mercurie, from Medieval Latin mercurius, from Latin, the god] a :  a silver-white poisonous heavy metallic element that is liquid at ordinary temperatures and is used especially in batteries, in dental amalgam, and in scientific instruments —called also quicksilver — see element table b :  the column of mercury in a thermometer or barometer; also :  temperature <the mercury rose above 70 degrees>

  3. 3 capitalized :  the planet nearest the sun — see planet table

Examples of mercury in a sentence

  1. In the summer, the mercury can reach over 100 degrees Fahrenheit.

Origin of mercury

Latin Mercurius, Roman god and the planet

First Known Use: 14th century

MERCURY Defined for Kids


noun mer·cu·ry \ˈmər-kyə-rē\

Definition of mercury for Students

  1. 1 :  a heavy silvery white poisonous metallic chemical element that is liquid at ordinary temperatures

  2. 2 :  the column of mercury in a thermometer or barometer

  3. 3 cap :  the planet that is nearest the sun and has a diameter of about 3000 miles (4700 kilometers)

Medical Dictionary


noun mer·cu·ry \ˈmər-kyə-rē, -k(ə-)rē\

Medical Definition of mercury

plural mercuries

  1. 1:  a heavy silver-white poisonous metallic element that is liquid at ordinary temperatures and used especially in scientific instruments—symbol Hg; called also quicksilver; see element table

  2. 2:  a pharmaceutical preparation containing mercury or a compound of it

Biographical Note for mercury

Mercury,, Roman mythological character. In Roman mythology Mercury became identified with the Greek god Hermes. This god was known especially as the fleet-footed messenger of the gods. He was also the god of science and the arts and the patron of travelers and athletes. He is typically represented in art as a young man wearing a winged helmet and winged sandals and bearing a caduceus. The metal mercury was named after him most probably because he symbolizes mobility.

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expressing little or no emotion

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