apparitional

haamumainen puhekieltä Of or pertaining to an apparition or apparitions; ghostly; immaterial; spectral.
1908, w:Henry_James Henry James, "The Jolly Corner," ch. 2,

People enough, first and last, had been in terror of apparitions, but who had ever before so turned the tables and become himself, in the apparitional world, an incalculable terror?