Pluto

noun
Plu·​to | \ ˈplü-(ˌ)tō How to pronounce Pluto (audio) \

Definition of Pluto

1 : the Greek god of the underworld — compare dis
2 [New Latin] : a dwarf planet occupying an orbit that crosses the orbit of Neptune

Is Pluto a planet?: Usage Guide

In 2006 the International Astronomical Union defined planet in such a way as to exclude Pluto, reclassifying it instead as a dwarf planet. Although discussion of the matter continues, the change has been widely accepted.

First Known Use of Pluto

14th century, in the meaning defined at sense 1

History and Etymology for Pluto

Latin Pluton-, Pluto, from Greek Ploutōn

Keep scrolling for more

Learn More about Pluto

Time Traveler for Pluto

Time Traveler

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

See more words from the same century

Statistics for Pluto

Cite this Entry

“Pluto.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., https://www.merriam-webster.com/dictionary/Pluto. Accessed 15 December 2019.

Keep scrolling for more

More Definitions for Pluto

Pluto

noun
How to pronounce Pluto (audio)

English Language Learners Definition of Pluto

: the object in our solar system that in the past was thought to be the planet farthest from the sun but that is no longer considered to be a planet

Pluto

noun
Plu·​to | \ ˈplü-tō How to pronounce Pluto (audio) \

Kids Definition of Pluto

: a celestial object that orbits the sun at an average distance of 3.7 million miles (5.9 million kilometers) and has a diameter of about 1500 miles (2300 kilometers) and is often considered one of the planets

Keep scrolling for more

More from Merriam-Webster on Pluto

Rhyming Dictionary: Words that rhyme with Pluto

Spanish Central: Translation of Pluto

Nglish: Translation of Pluto for Spanish Speakers

Britannica English: Translation of Pluto for Arabic Speakers

Comments on Pluto

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

WORD OF THE DAY

delight or enjoyment

Get Word of the Day daily email!

Test Your Vocabulary

Great Scrabble Words—A Quiz

  • scrabble tiles that read scrabble quiz
  • Which of the following Q-without-U words means the number five in cards or dice?
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!