Nkisi or Nkishi (plural varies: minkisi, zinkisi, or nkisi) are spirits, or an object that a spirit inhabits. It is frequently applied to a variety of objects used throughout the Congo Basin in Central Africa that are believed to contain spiritual powers or spirits. The term and its concept have passed with the Atlantic slave trade to the Americas.
The current meaning of the term derives from the root, *-kitį- referring to a spiritual entity, or material objects in which it is manifested or inhabits in Proto-Njila, an ancient subdivision of the Bantu language family.
In its earliest attestations in Kikongo dialects in the early seventeenth century it was transliterated as "mokissie" (in Dutch), as the mu- prefix in this noun class were still pronounced. It was reported by Dutch visitors to Loango in the 1668 book Description of Africa as referring both to a material item and the spiritual entity that inhabits it. In the sixteenth century, when the Kingdom of Kongo was converted to Christianity, ukisi (a substance having characteristics of nkisi) was used to translate "holy" in the Kikongo Catechism of 1624.
In the eighteenth century, the mu- prefix evolved into a simple nasal n-, so the modern spelling is properly n'kisi, but many orthographies spell it nkisi (there is no language-wide accepted orthography of Kikongo).
Close communication with ancestors and belief in the efficacy of their powers are closely associated with minkisi in Kongo tradition. Among the peoples of the Congo Basin, especially the Bakongo and the Songye people of Kasai, exceptional human powers are frequently believed to result from some sort of communication with the dead. People known as banganga (singular: nganga) work as healers, diviners, and mediators who defend the living against black magic (witchcraft) and provide them with remedies against diseases resulting either from witchcraft or the demands of bakisi (spirits), emissaries from the land of the dead.