Pluto

noun

Plu·​to ˈplü-(ˌ)tō 

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

Three’s Company is now available to view on Pluto TV. —Marc Berman, Forbes, 15 Mar. 2025

The Mars Curiosity and Perseverance rovers and the New Horizons spacecraft that visited Pluto in 2015 have all used RTGs. —Benjamin Roulston, The Conversation, 14 Mar. 2025

These include planets and thousands of asteroids, comets, icy worlds beyond Pluto, and interstellar objects that occasionally transit through the Solar System. —Ars Technica, 13 Mar. 2025

Despite not technically being a planet anymore, Pluto has five moons. —Laura Baisas, Popular Science, 12 Mar. 2025

Word History

Etymology

Latin Pluton-, Pluto, from Greek Ploutōn

First Known Use

14th century, in the meaning defined at sense 1

Rhymes for Pluto

• basuto
• prosciutto

Kids Definition

Pluto

noun

Plu·​to ˈplüt-ō 

: a large object in the outermost part of the solar system that is often considered one of the planets see note at planet