: a purificatory ceremony performed as a preliminary to entering a holy place, as a means of removing bloodguiltiness, on the occasion of a birth, marriage, or death, or as a means of ceremonially cleansing a house, a city, army, or a whole people on some special occasion
lustration with water is a prominent feature in Babylonian cult—W. L. Wardle
b
: an act or instance of cleansing especially by moral or spiritual purification
the lustration of penitents—Lawrence Durrell
the Deluge as a type of the world's lustration—F. W. Farrar