- Glossary definition: Mass

Main service of the Roman Catholic Church, commemorating Christ's death and resurrection. High Mass is sung, Low Mass is spoken. The Ordinary of the Mass, the normally recurrent parts of the liturgy, consists of the Kyrie eleison (Lord have mercy), Gloria (Glory be to God in the highest), Credo (I believe), Sanctus (Holy, holy, holy), Benedictus (Blessed be he who comes in the name of the Lord) and the Agnus Dei (Lamb of God). These are the texts most often set. The Proper of the Mass changes from day to day, according to the season or the occasion.