mer·​cu·​ry | \ ˈmər-kyə-rē How to pronounce mercury (audio) , -k(ə-)rē \
plural mercuries

Definition of mercury

1a 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 [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 Chemical Elements Table
b : the column of mercury in a thermometer or barometer also : temperature the mercury rose above 70 degrees
3 capitalized : the planet nearest the sun — see Planets Table

Examples of mercury in a Sentence

In the summer, the mercury can reach over 100 degrees Fahrenheit.
Recent Examples on the Web The lake is also releasing mercury, a toxic metal that could now be accumulating in Alaska’s water sources, as well as radon gas. Lois Parshley, Anchorage Daily News, 3 May 2022 Shard #742's residue included animal fats, plant oils, resin, salts, and mercury, with a bit of sodium thrown in. Jennifer Ouellette, Ars Technica, 3 May 2022 Alabama Power has also been fined on multiple occasions after coal ash ponds in Mobile and elsewhere in the state were found to be contaminating groundwater with substances such as mercury, lead, and selenium. Dennis Pillion |, al, 21 Apr. 2022 Residents are encouraged to bring fever thermometers containing mercury, a highly toxic chemical to humans and the environment, for proper disposal. Elissa Welle, Detroit Free Press, 31 Mar. 2022 The preferred tool in the process is mercury, which collects and purifies traces found in the soil. Washington Post, 19 Mar. 2022 The suit cited a state Department of Public Health report that some skin-lightening creams contain mercury, which can cause both kidney damage and harm to reproductive health. Bob Egelko, San Francisco Chronicle, 11 Mar. 2022 Residuals are produced by burning coal in power plants and contain pollutants like mercury, cadmium and arsenic that can taint water supplies and air if not disposed of properly. Zayna Syed, The Arizona Republic, 10 Feb. 2022 Today, the fish is farmed safely, and the EPA and FDA have identified it as a good choice for children and breastfeeding mothers because of its low levels of mercury. Bethany Thayer, Detroit Free Press, 19 Mar. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'mercury.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of mercury

14th century, in the meaning defined at sense 1a

History and Etymology for mercury

Latin Mercurius, Roman god and the planet

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Time Traveler for mercury

Time Traveler

The first known use of mercury was in the 14th century

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Dictionary Entries Near mercury

mercurous chloride


Mercury's staff

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Statistics for mercury

Last Updated

18 May 2022

Cite this Entry

“Mercury.” Dictionary, Merriam-Webster, Accessed 24 May. 2022.

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More Definitions for mercury


mer·​cu·​ry | \ ˈmər-kyə-rē How to pronounce mercury (audio) \

Kids Definition of mercury

1 : a heavy silvery white poisonous metallic chemical element that is liquid at ordinary temperatures
2 : the column of mercury in a thermometer or barometer
3 capitalized : the planet that is nearest the sun and has a diameter of about 3000 miles (4700 kilometers)


mer·​cu·​ry | \ ˈmər-kyə-rē, -k(ə-)rē How to pronounce mercury (audio) \
plural mercuries

Medical Definition of mercury

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 Chemical Elements Table
2 : a pharmaceutical preparation containing mercury or a compound of it

More from Merriam-Webster on mercury

Nglish: Translation of mercury for Spanish Speakers

Britannica English: Translation of mercury for Arabic Speakers Encyclopedia article about mercury


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