a spherical celestial body revolving about the sun, similar to a planet but not large enough to gravitationally clear its orbital region of most or all other celestial bodies. Pluto is a dwarf planet.
When To Capitalize “Earth”When it comes to writing, this common English word confuses many native speakers who aren’t sure whether to use Earth or earth. Why is this an issue? Earth can be either a proper noun or a common noun. In English, proper nouns (nouns which signify a particular person, place, or thing) are capitalized. Following this rule, when Earth is discussed as a specific planet or …
Origin of dwarf planet
First recorded in 1990–95
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for dwarf planet
any celestial body within the solar system that is larger than a satellite but smaller than a planet, and that orbits the sun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012