in a general sense, signifies the washing or purifying something with water.

in a religious sense, a ceremony in use among the ancients, and still practised in several parts of the world: it consisted in washing the body, which was always done before sacrificing, or even entering their houses. Ablutions appear to be as old as any ceremonies, and external worship itself. Moses enjoined them; the heathens adopted them; and Mahomet and his followers have continued them: thus they have got footing among most nations, and make a considerable part of most established religions.—The Egyptian priests had their diurnal and nocturnal ablutions; the Grecians their sprinklings; the Romans their lustrations and lavations; the Jews their washing of hands and feet, beside their baptisms.—The ancient Christians had their ablutions before communion; which the Romish church still retain before their mass, sometimes after. The Syrians, Copts, &c. have their solemn washings on Good Friday: the Turks their greater and lesser ablutions; their Ghast and Wodou, their Aman, Taharat, &c.