The
ordinary, in
Roman Catholic and other
Western Christian liturgies, refers to the part of the
Eucharist or of the
canonical hours that is reasonably constant without regard to the date on which the service is performed. It is contrasted to the
proper, which is that part of these liturgies that varies according to the date, either representing an observance within the
liturgical year, or of a particular
saint or significant event, and to the
common, which contains those parts that are common to an entire category of saints, such as
apostles or
martyrs.