Plu·​to ˈplü-(ˌ)tō How to pronounce Pluto (audio)
: the Greek god of the underworld compare dis
[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 Syrah Scorpios are the water sign co-ruled by Pluto, the planet of transformation, and Mars, the planet of action and energy. Karla Walsh, Better Homes & Gardens, 16 Nov. 2023 Like other icy worlds of the outer solar system, such as Europa or possibly Pluto, Ganymede probably has an ocean lurking under its icy crust. Popular Science, 8 Nov. 2023 The 2023 EMAs would usually broadcast on MTV in over 150 countries in addition to streaming online via Pluto TV and Paramount+. Carita Rizzo, Rolling Stone, 6 Nov. 2023 Featuring Mickey Mouse, Minnie Mouse, Goofy, Pluto, Donald Duck and Daisy Duck in Mickey’s Toontown at Disneyland Park, the Boeing 737-800 also includes Chip ‘n’ Dale on the boarding doors and winglets. Nicholas Rice, Peoplemag, 4 Nov. 2023 The company’s leadership also believes that 2022 marked the peak investment year for its streaming ambitions — powered by Paramount+ and Pluto TV — and that this year losses will be overall lower than last year, an encouraging sign. Erik Hayden, The Hollywood Reporter, 3 Nov. 2023 Familiar faces The passengers on SpaceShipTwo Thursday included Alan Stern, a planetary scientist perhaps most famous for leading NASA's New Horizons mission, which completed the first robotic exploration of Pluto in 2015. Stephen Clark, Ars Technica, 3 Nov. 2023 Some scientists even argue that Pluto has a subsurface ocean. Quanta Magazine, 2 Nov. 2023 In 2016 astronomers proposed Planet Nine’s existence as a way of explaining a strange sort of clustering observed in several small bodies found in and beyond the Kuiper Belt, a distant region of the solar system containing Pluto and many other objects. Nola Taylor Tillman, Scientific American, 25 Oct. 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'Pluto.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


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

Dictionary Entries Near Pluto

Cite this Entry

“Pluto.” Dictionary, Merriam-Webster, Accessed 30 Nov. 2023.

Kids Definition


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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