intangibility (n.)

• airiness
• evanescence
• flimsiness
• ghostliness
• immateriality
• impalpability
• imperceptibility
• incorporeality
• insubstantiality
• invisibility
• mistiness
• occultism
• otherworldliness
• shadowiness
• spirituality
• subtlety
• supernaturalism
• tenuity
• unreality
• vagueness