- apparition, phantom, phantasm, phantasma, specter, spectre - a ghostly appearing figure; "we were unprepared for the apparition that confronted us"
--1 is a kind of spirit, disembodied spirit
--1 has particulars: Flying Dutchman - apparition, phantom, phantasm, phantasma, shadow - something existing in perception only; "a ghostly apparition at midnight"
--2 is a kind of illusion, semblance
--2 has particulars:unidentified flying object, UFO, flying saucer; Flying Dutchman; ghost, shade, spook, wraith, specter, spectre