Synonyms and related words :
airiness, bodilessness, ethereality, evanescence, flimsiness, ghostliness, immateriality, immaterialness, impalpability, imperceptibility, imponderability, incorporeality, incorporeity, inextension, insubstantiality, invisibility, mistiness, nonexteriority, occult phenomena, occultism, otherworldliness, psychical research, psychicism, psychics, psychism, shadowiness, spirit world, spirituality, spirituousness, subtility, subtlety, supernaturalism, tenuity, tenuousness, the occult, unconcreteness, unearthliness, unreality, unsolidity, unsubstantiality, unsubstantialness, unworldliness, vagueness