Pluto

noun

Plu·​to ˈplü-(ˌ)tō How to pronounce Pluto (audio)
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.

Examples of Pluto in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The baby hippo, who doesn't yet have a name, was born to parents Pluto and Posie. Greta Cross, USA Today, 12 July 2025 Diehard fans of Big Brother, of course, are anxiously awaiting the live 24/7 feeds, which will be accessible on paramount+ Premium and Pluto TV effective on Sunday, July 13 at 9:30 p.m. ET following the second telecast on CBS. Marc Berman, Forbes.com, 11 July 2025 Born in the real 2006, Vic would’ve entered an America launching Twitter, discovering Taylor Swift, transporting Saddam Hussein, and reclassifying Pluto as a dwarf. Alison Foreman, IndieWire, 11 July 2025 They are often tied to the shadow aspects of life due to their planetary rulers: Mars (the planet of war) and Pluto (the planet of intensity). Kyle Thomas, People.com, 11 July 2025 See All Example Sentences for Pluto

Word History

Etymology

Latin Pluton-, Pluto, from Greek Ploutōn

First Known Use

14th century, in the meaning defined at sense 1

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

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Cite this Entry

“Pluto.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Pluto. Accessed 18 Jul. 2025.

Kids Definition

Pluto

noun
Plu·​to ˈplüt-ō How to pronounce Pluto (audio)
: a large object in the outermost part of the solar system that is often considered one of the planets see note at planet

More from Merriam-Webster on Pluto

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