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

No children are allowed at the mine, and toxic chemicals like mercury and arsenic are reduced and contained so no leakages can damage the environment or communities around. Nicole Phelps, Vogue, "Jeweler Pippa Small’s New Collection Was Hand-Forged 4,000 Meters Up in Bolivia," 22 Oct. 2018 The intricate metallic gown was crafted from velvet lamé and lace, with mercury and stone embellishments throughout. Andrea Park, Glamour, "Lady Gaga Wore Silver Givenchy to the 'A Star Is Born' Premiere, and It Will Slay You," 25 Sep. 2018 The city last experienced a 100-degree temperature on July 6, 2012, when the temperature jumped to 103 degrees, and that was the hottest since July 13, 1995, when the mercury hit 104 degrees. Tom Skilling,, "Temperature and rainfall totals are jumping," 27 June 2018 My 30-plus marathons include 2012 in Boston, when the mercury hit 87 degrees. Jon Chesto,, "Rain drops like tiny darts, blisters that cut like a serrated knife. A Globe reporter on the worst of what runners are braving out there," 16 Apr. 2018 The mercury in Costa Mesa is expected to rise to the mid-90s Friday and through the weekend. Hannah Fry,, "Big surf and high temperatures will greet beach crowds this week," 3 July 2018 The hottest days will be Saturday and Sunday, when the mercury is expected to top out at 86 both days. Anthony R. Wood,, "Philly braces for what could be a 10-day heat wave; Shore likely to be spared," 28 June 2018 The mercury regulation is not universally opposed within the coal industry. David Grossman, Popular Mechanics, "EPA Wants To Hollow Out Regulations That Safeguard Against Mercury Poisoning," 28 Dec. 2018 Opt for Safe and Sustainable Types Bypass fish varieties high in mercury (typically shark, swordfish, king mackerel, and tuna). Woman's Day, "Everything You Need to Know About Picking Out and Preparing Fish," 19 Sep. 2018

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.

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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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Statistics for mercury

Last Updated

26 Apr 2019

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Time Traveler for mercury

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

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English Language Learners Definition of mercury

: a silver metal that is liquid at normal temperatures
: the mercury in a thermometer that shows the air's temperature
: the planet that is closest to the sun


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

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More from Merriam-Webster on mercury

Spanish Central: Translation of mercury

Nglish: Translation of mercury for Spanish Speakers

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

Comments on mercury

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a secret plot to overthrow a government

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