Definition of geoplanarian in English:

geoplanarian

adjective

  • Of or relating to the belief that the earth is flat.

noun

  • A person who holds this belief; = "flat-earther".

Origin

Early 20th century; earliest use found in Rudyard Kipling (1865–1936), writer and poet. From geo- + classical Latin plānus flat + -arian.

Pronunciation

geoplanarian

/ˌdʒiːə(ʊ)pləˈnɛːrɪən/