1) A service at night prior to a major feast or other important observance. The vigil anticipates and begins the commemoration of the following day. It may allow the participants an opportunity to reflect on the meaning of the next day's service. Scripture texts that will be used at the service on the following day may be introduced at a vigil. Christian vigils have been observed since the early years of the church. The Easter Vigil dates from at least the second century, and it is described in Hippolytus's Apostolic Tradition. The candidates for baptism spent the night in vigil, where they listened to readings and instructions. At cockcrow, the baptismal water was blessed and the candidates were baptized. The pilgrim Egeria mentions a vigil at the tomb in Jerusalem on Good Friday in the fourth century. Ancient sacramentaries provide evidence of a Pentecost vigil. The 1662 BCP lists sixteen feasts that were preceded by a vigil. Although the Easter Vigil was not retained as a vigil by the 1549 Prayer Book, the 1979 BCP includes a rite for the Great Vigil of Easter (pp. 285-295). The 1979 BCP also provides for a Vigil of Pentecost (BCP, p. 227), which resembles the Easter Vigil in a simplified form. The BCP also includes prayers for a vigil prior to burial of the dead (BCP, pp. 465-466). Psalms, lessons, and collects from the burial service may be used at this vigil. The Litany at the Time of Death may also be used. The BOS provides vigils for Christmas Eve, the Eve of the Baptism of our Lord, and the Eve of All Saints' Day or the Sunday after All Saints' Day. The BOS also includes a Vigil on the Eve of Baptism and a vigil Service for New Year's Eve (Eve of Holy Name). 2) The term may also indicate a watch in the presence of the body of a deceased person prior to burial. See Wake.
Glossary definitions provided courtesy of Church Publishing Incorporated, New York, NY,(All Rights reserved) from "An Episcopal Dictionary of the Church, A User Friendly Reference for Episcopalians," Don S. Armentrout and Robert Boak Slocum, editors.