flat-earth

flat-earth (not comparable)

1. Of or relating to the theory that planet Earth is flat.
   • 1912, Arthur Conan Doyle, The Lost World […], London; New York, N.Y.: Hodder and Stoughton, →OCLC:

     So looks the Shakespearean who is confronted by a rancid Baconian, or the astronomer who is assailed by a flat-earth fanatic.