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

With Pluto also in your sign, expect some deep, transformative moments that bring you closer to your authentic self. —Valerie Mesa, People.com, 1 Jan. 2025

In 2017, Pluto added a more traditional video-on-demand library; like those of Plex, Shout TV, Tubi and their ilk, those films are also played with ad breaks to keep the service free. —Jason Bailey, New York Times, 30 Dec. 2024

For example, Pluto is considered a TNO but not a centaur. —Paul Smaglik, Discover Magazine, 27 Dec. 2024

On January 3, Mars opposes Pluto for the second time since early November, intensifying the stakes of your current mission. —Steph Koyfman, Condé Nast Traveler, 27 Dec. 2024

Word History

Etymology

Latin Pluton-, Pluto, from Greek Ploutōn

First Known Use

14th century, in the meaning defined at sense 1

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