a demon, or the soul of a dead person, that enters the body of a living person and directs the person's conduct, exorcism being possible only by a religious ceremony.
dyb·buk (dĭb'ŏŏk, dē-bōōk') n.
pl.dyb·buks or dyb·buk·im (dĭ-bŏŏk'ĭm, dē'bōō-kēm') In Jewish folklore, the wandering soul of a dead person that enters the body of a living person and controls his or her behavior.
[Yiddish dibek, from Hebrew dibbūq, probably from dābaq, to cling; see dbq in Semitic roots.]
1903, "malevolent spirit of a dead person possessing the body of a living one," from Jewish folklore, from Heb. dibbuk, from dabak "to cling, cleave to."