Definition of "earthbound"

"Music, Smiley, music! Now the vibrations should be better." "The higher spirits cannot reach earth-bound folk," said Mailey.

1925 July – 1926 May, A[rthur] Conan Doyle, “(please specify the chapter number)”, in The Land of Mist (eBook no. 0601351h.html), Australia: Project Gutenberg Australia, published April 2019

[B]ut only too often séances degenerate into pure sorcery or necromancy, attracting all kinds of undeveloped and earth-bound entities.

1936, Rollo Ahmed, The Black Art, London: Long, page 231