Definition of earthman in US English:

earthman

(also eorðman)

noun

  • 1Chiefly Science Fiction. A person (especially a man) who is a native or inhabitant of the planet earth.

  • 2With capital initial. A member (especially a man) of an indigenous southern African people of relatively short stature, probably identical to the Bushmen or San, but believed to dwell or shelter in caves or hollows in the ground, and thus distinguished from them. Compare earthwoman. Now historical.

Origin

Middle English (in an earlier sense). In some forms from earth + man. In some forms from the genitive of earth + man.