mercury

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

|Updated on: 5 Jul 2018

Definition of mercury

plural mercuries

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

[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

See mercury defined for English-language learners

See mercury defined for kids

Examples of mercury in a Sentence

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

Recent Examples of mercury from the Web

Police subsequently searched the home of the 56-year-old suspect and found substances used to make poison, including mercury, lead and cadmium.

— darko janjevic, USA TODAY, "German man suspected of killing 21 co-workers by poisoning their food," 29 June 2018
Power plant emissions from mercury have dropped 86 percent since 2000, according to Ceres.

— l.m. sixel, Houston Chronicle, "Power plant emissions fall as producers shift from coal," 26 June 2018
The Mayo Clinic recommends high-protein foods like lean meat, eggs, dairy, legumes, and low-mercury seafoods while breastfeeding.

— taylyn washington-harmon, SELF, "Tia Mowry Says These Foods Help Keep Up Her Milk Supply," 22 June 2018
The men here often add liquid mercury to dirt in their search for gold, and the silver water and earth suggest the resources of an alien world.

— ben sachs, Chicago Reader, "Chicago Underground Film Festival: Gold and copper miners tough it out in Good Luck," 5 June 2018
The family called 911 and fire officials recovered even more mercury from the AC unit across both floors.

— scott berson, miamiherald, "Business owner put poisonous mercury in family's air conditioner after complaints, DA says," 31 May 2018
On Tuesday, the district posted information on its website that said tests of eight water samples taken at Van Hoosen and Adams did not detect mercury.

— detroit free press staff, Detroit Free Press, "Rochester school officials: Water is safe," 22 May 2018
Over-the-counter fish oils are not regulated by the FDA and may not be filtered for heavy metals such as mercury.

— david becker, Philly.com, "Why this cardiologist is no longer recommending fish oil supplements," 1 May 2018
With the mercury expected to rise to 105 degrees by the end of the week, the white tents in Tornillo, Texas — a morally jarring new twist in the rise of America’s immigration gulag — went up just in time for Father’s Day weekend.

— will bunch, Philly.com, "In America's moral civil war, whose side is God on, anyway? | Will Bunch," 17 June 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.

Origin and Etymology of mercury

Latin Mercurius, Roman god and the planet

NEW! Time Traveler

First Known Use: 14th century

in the meaning defined at sense 1a

See Words from the same year

MERCURY Defined for English Language Learners

mercury

noun

Definition of mercury for English Language Learners

: 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

MERCURY Defined for Kids

mercury

noun mer·cu·ry \ ˈmər-kyə-rē \

Definition of mercury for Students

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)

Medical Dictionary

mercury

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

medical Definition of mercury

plural mercuries

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

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.