[ flat-ur-ther ]
/ ˈflætˈɜr θər /
a person who adheres to the idea that the earth is flat.
a person who clings to an idea or theory that has long been proved wrong.
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 flat-earther
1930–35; flat earth + -er1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for flat-earther
informal a person who does not accept or is out of touch with the realities of modern life
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