In folklore, a ghost (sometimes known as an apparition, haunt, phantom, poltergeist, shade, specter or spectre, spirit, spook, and wraith) is the soul or spirit of a dead person or animal that can appear to the living. In ghostlore, descriptions of ghosts vary widely from an invisible presence to translucent or barely visible wispy shapes, to realistic, lifelike visions. The deliberate attempt to contact the spirit of a deceased person is known as necromancy, or in spiritism as a séance.
The belief in the existence of an afterlife, as well as manifestations of the spirits of the dead, is widespread, dating back to animism or ancestor worship in pre-literate cultures. Certain religious practices—funeral rites, exorcisms, and some practices of spiritualism and ritual magic—are specifically designed to rest the spirits of the dead. Ghosts are generally described as solitary, human-like essences, though stories of ghostly armies and the ghosts of animals rather than humans have also been recounted. They are believed to haunt particular locations, objects, or people they were associated with in life.
The overwhelming consensus of science is that ghosts do not exist. Their existence is impossible to falsify, and ghost hunting has been classified as pseudoscience. Despite centuries of investigation, there is no scientific evidence that any location is inhabited by spirits of the dead.
The English word ghost continues Old English gāst, from Proto-Germanic *gaistaz. It is common to West Germanic, but lacking in North Germanic and East Germanic (the equivalent word in Gothic is ahma, Old Norse has andi m., önd f.). The prior Proto-Indo-European form was *ǵʰéysd-os, from the root *ǵʰéysd- denoting “fury, anger” reflected in Old Norse geisa “to rage”. The Germanic word is recorded as masculine only, but likely continues a neuter s-stem. The original meaning of the Germanic word would thus have been an animating principle of the mind, in particular capable of excitation and fury (compare óðr). In Germanic paganism, “Germanic Mercury”, and the later Odin, was at the same time the conductor of the dead and the “lord of fury” leading the Wild Hunt.
Besides denoting the human spirit or soul, both of the living and the deceased, the Old English word is used as a synonym of Latin spiritus also in the meaning of “breath” or “blast” from the earliest attestations (9th century). It could also denote any good or evil spirit, such as angels and demons; the Anglo-Saxon gospel refers to the demonic possession of Matthew 12:43 as se unclæna gast. Also from the Old English period, the word could denote the spirit of God, viz. the “Holy Ghost”.
The now-prevailing sense of “the soul of a deceased person, spoken of as appearing in a visible form” only emerges in Middle English (14th century). The modern noun does, however, retain a wider field of application, extending on one hand to “soul”, “spirit”, “vital principle”, “mind”, or “psyche”, the seat of feeling, thought, and moral judgement; on the other hand used figuratively of any shadowy outline, or fuzzy or unsubstantial image; in optics, photography, and cinematography especially, a flare, secondary image, or spurious signal.
The synonym spook is a Dutch loanword, akin to Low German spôk (of uncertain etymology); it entered the English language via American English in the 19th century. Alternative words in modern usage include spectre (altn. specter; from Latin spectrum), the Scottish wraith (of obscure origin), phantom (via French ultimately from Greek phantasma, compare fantasy) and apparition. The term shade in classical mythology translates Greek σκιά, or Latin umbra, in reference to the notion of spirits in the Greek underworld. “Haint” is a synonym for ghost used in regional English of the southern United States, and the “haint tale” is a common feature of southern oral and literary tradition. The term poltergeist is a German word, literally a “noisy ghost”, for a spirit said to manifest itself by invisibly moving and influencing objects.
Wraith is a Scots word for ghost, spectre, or apparition. It appeared in Scottish Romanticist literature, and acquired the more general or figurative sense of portent or omen. In 18th- to 19th-century Scottish literature, it also applied to aquatic spirits. The word has no commonly accepted etymology; the OED notes “of obscure origin” only. An association with the verb writhe was the etymology favored by J. R. R. Tolkien. Tolkien’s use of the word in the naming of the creatures known as the Ringwraiths has influenced later usage in fantasy literature. Bogey or bogy/bogie is a term for a ghost, and appears in Scottish poet John Mayne’s Hallowe’en in 1780.
A revenant is a deceased person returning from the dead to haunt the living, either as a disembodied ghost or alternatively as an animated (“undead”) corpse. Also related is the concept of a fetch, the visible ghost or spirit of a person yet alive.