voodoo n.

religious witchcraft of Haiti and Southern U.S., ultimately of African origin, 1850, from Louisiana French voudou, from a West African language (such as Ewe and Fon vodu "spirit, demon, deity," also Vandoo, supposedly the name of an African deity, from a language of Dahomey). Compare vodun "fetish connected with snake worship in Dahomey," said to be from vo "to be afraid," or vo "harmful." The verb is attested from 1880.