Commatres is a term sometimes used in ancient writers to denote sponsors in baptism. Commemoration, in its liturgical use, designates:
1. The recitation of the names of those for whom intercession is made in the mass. SEE DIPTYCH.
2. The introduction of the names of certain saints or events in the divine office. Such commemorations are generally of the cross, of the Virgin Mary, of St. Peter and St. Paul, and for peace.
⇒See also the International Standard Bible Encyclopedia.
3. According to the rubrics of the Roman breviary, when a greater festival falls on the day of a "simple" festival, the latter is "commemorated" by the introduction of certain portions of its proper service into that of the greater festival.
4. In the Church of England "commemoration" takes place when two festivals concur, and the office for the greater is used, while the collect only of the lesser is said; or when a festival coincides with a greater Sunday; or a festival of the second class falls on a greater week-day, and the same rule is observed. In Lent, Advent, on ember-days, and greater ferials, a special collect is used.