In Jewish mysticism and folklore, a dybbuk is an evil spirit which enters a person, takes over their personality, precipitates mental illness, speaks through their voice and generally causes trouble.
Dybbukim first appear in talmudic writings. According to early views they were devils or demons. Later mystics posited that dybbukim could be the spirits of dead sinners, who were so evil in their lifetimes that their souls could find no resting place in the world to come and were therefore compelled to take refuge in the bodies of innocent living victims.
Kabbalistic works, at least from the 16th century onwards, sometimes contain instructions and protocols for the exorcism of dybbuks, ceremonies to drive them out of the bodies they have colonised.
The dybbuk is short for the dybbuk m'ruach ha- ra'ah, meaning "cleaving from the evil spirit." The word dybbuk itself is from the Hebrew "davak," which means to "stick" or "cleave." (Devek means "glue" in modern Hebrew.)
