A memorial in the Roman Rite of the Catholic Church is a lower-ranked feast day in honour of a saint, the dedication of a church, or a mystery of the religion.
All feast days are ranked according to their importance and named as "solemnities", or "feasts", or "memorials".[1]
Memorials are always supplanted by a coinciding solemnity, feast, Sunday, Ash Wednesday, Holy Week, or day of the Octave of Easter.