Source : Webster's Revised Unabridged Dictionary (1913)

Antichthon \An*tich"thon\, n.; pl. {Antichthones}. [Gr. ?; ?
   against + ? the earth.]
   1. A hypothetical earth counter to ours, or on the opposite
      side of the sun. --Grote.

   2. pl. Inhabitants of opposite hemispheres. --Whewell.