comet

noun
com·​et | \ ˈkä-mət How to pronounce comet (audio) \

Definition of comet

: a celestial body that appears as a fuzzy head usually surrounding a bright nucleus, that has a usually highly eccentric orbit, that consists primarily of ice and dust, and that often develops one or more long tails when near the sun

Keep scrolling for more

Other Words from comet

cometary \ ˈkä-​mə-​ˌter-​ē How to pronounce cometary (audio) \ adjective
cometic \ kə-​ˈme-​tik How to pronounce cometic (audio) , kä-​ \ adjective

Examples of comet in a Sentence

Recent Examples on the Web

Astronomer Michelle Young works to save San Francisco after a rogue comet causes meteors to hit the city. Los Angeles Times, "Movies on TV this week Sept. 15, 2019: ‘Alien,’ ‘Aliens’ and more," 13 Sep. 2019 Until recently, scholars were open to the idea that these clouds were the remains of an asteroid or comet. Michael Greshko, National Geographic, "Colossal volcano behind 'mystery' global cooling finally found," 23 Aug. 2019 An asteroid or comet would have to venture very close to the Earth to be torn apart by tidal forces and form a ring around the Earth. Vahe Peroomian, The Conversation, "A brief astronomical history of Saturn’s amazing rings," 14 Aug. 2019 By mass, the comet is around 80 percent dust and just 20 percent ice, notes McCaughrean. Julissa Treviño, Smithsonian, "Comet “Snowstorm” Swirling in This Stunning GIF Is a Tricky Illusion," 30 Apr. 2018 The comet, dubbed C/2019 Q4, was discovered Aug. 30 by Gennady Borisov at an observatory in Nauchnij, Crimea. Doyle Rice, USA TODAY, "It came from outer space: Newly discovered comet is likely interstellar visitor," 12 Sep. 2019 More data could help scientists understand whether water on the moon has been deposited by comets or asteroids over millennia, or if water vapor is emerging from the lunar soil due to some chemical reaction. Tim Fernholz, Quartz, "India’s lunar lander is missing, but Chandrayaan-2 can still make important discoveries," 6 Sep. 2019 An even greater number, 68 percent, attached such importance to monitoring asteroids, comets, or other objects from space that could strike the planet. Eric Berger, Ars Technica, "Americans aren’t interested in the Moon and Mars—and that’s understandable," 20 June 2019 The fireballs are released from the comet 109P/Swift-Tuttle during its numerous returns to the inner solar system. Christopher Brito, CBS News, "When and where to watch the Perseid meteor shower, which peaks tonight," 12 Aug. 2019

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

See More

First Known Use of comet

before the 12th century, in the meaning defined above

History and Etymology for comet

Middle English comete, from Old English cometa, from Latin, from Greek komētēs, literally, long-haired, from koman to wear long hair, from komē hair

Keep scrolling for more

Learn More about comet

Statistics for comet

Last Updated

4 Oct 2019

Look-up Popularity

Time Traveler for comet

The first known use of comet was before the 12th century

See more words from the same century

Keep scrolling for more

More Definitions for comet

comet

noun

English Language Learners Definition of comet

: an object in outer space that develops a long, bright tail when it passes near the sun

comet

noun
com·​et | \ ˈkä-mət How to pronounce comet (audio) \

Kids Definition of comet

: a small bright heavenly body that develops a cloudy tail as it moves in an orbit around the sun

Keep scrolling for more

More from Merriam-Webster on comet

Spanish Central: Translation of comet

Nglish: Translation of comet for Spanish Speakers

Britannica English: Translation of comet for Arabic Speakers

Britannica.com: Encyclopedia article about comet

Comments on comet

What made you want to look up comet? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

a topic to which one constantly reverts

Get Word of the Day daily email!

Test Your Vocabulary

Where in the World? A Quiz

  • peter bruegel tower of babel painting
  • What language does pajama come from?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Syn City

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!