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

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

Dictionary Entries Near Pluto

pluteus

Pluto

plutocracy

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Statistics for Pluto

Cite this Entry

“Pluto.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Pluto. Accessed 18 Aug. 2022.

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More Definitions for Pluto

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 billion miles (5.9 billion kilometers) and has a diameter of about 1500 miles (2300 kilometers) and is sometimes considered one of the planets

More from Merriam-Webster on Pluto

Nglish: Translation of Pluto for Spanish Speakers

Britannica English: Translation of Pluto for Arabic Speakers

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