n. In a general sense, the act of washing; a cleansing or purification by water.n. Any ceremonial washing.n. In the Roman Catholic Church: The washing of the feet of the poor (John xiii. 14) on Maundy or Holy Thursday, called mandatum. The washing of the celebrant's hands before and after communion. In the Eastern Church, the purification of the newly baptized on the eighth day after baptism.n. In the Roman Catholic Church, the wine and water which after communion are separately poured into the chalice over the thumb and index-finger of the officiating priest, who drinks this ablution before going on with the closing prayers.n. In chem., the purification of bodies by the affusion of a proper liquor, as water to dissolve salts.n. In medicine, the washing of the body externally, as by baths, or internally, by diluent fluids.n. The water used in cleansing.