The epiclesis (also spelled epiklesis; from ἐπίκλησις "surname" or "invocation") refers to the invocation of one or several gods. In ancient Greek religion, the epiclesis was the epithet used as the surname given to a deity in religious contexts. The term was borrowed into the Christian tradition, where it designates the part of the Anaphora (Eucharistic Prayer) by which the priest invokes the Holy Spirit (or the power of God's blessing) upon the Eucharistic bread and wine in some Christian churches. In most Eastern Christian traditions, the Epiclesis comes after the Anamnesis (remembrance of Jesus' words and deeds); in the Western Rite it usually precedes. In the historic practice of the Western Christian Churches, the consecration is effected at the Words of Institution though during the rise of the Liturgical Movement, many denominations introduced an explicit epiclesis in their liturgies.
The Ancient Greek term epíklēsis (ἐπίκλησις; literally 'calling upon') can be translated as 'surname, additional name', or as 'invocation, appeal'.
In ancient Greek religion, the epiclesis was used as the surname that was associated with a deity during religious invocations, in contrast to the more general term 'epithet' (ἐπίθετον), which is used in poetic contexts. In the 2nd century AD, the Greek geographer Pausanias used the term 'epiclesis' to designate the appellation under which a deity was honoured in specific places or occasions.
In the Catholic Church, the Words of Institution are considered to be the moment of Transubstantiation (when, according to religious tradition, the eucharistic elements would change from bread and wine into the actual Body and Blood of Christ). In 2001, in the Pontifical Council for Promoting Christian Unity on admission to the Eucharist between Chaldean Catholic Church and Assyrian Church of the East issued a statement stating that the Words of Institution are dispersed euchologically in Liturgy of Addai and Mari, wherein the words are stated not in immediate sequence but throughout the Liturgy.