ghost - ghost is usually defined as the apparition of a deceased person, frequently similar in appearance to that person, and encountered in places he or she frequented, or in association with the person's former belongings. The word 'ghost' may also refer to the spirit or soul of a deceased person, or to any spirit or demon. Ghosts are often associated with haunting, which is, according to the Parapsychological Association, 'the more or less regular occurrence of paranormal phenomena associated with a particular locality (especially a building) and usually attributed to the activities of a discarnate entity; the phenomena may include apparitions, poltergeist disturbances, cold drafts, sounds of steps and voices, and various odors.'