E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A title applied in the Middle Ages to the Pope, and at a somewhat later period to other Church dignitaries. It is now restricted to priests and choir monks among the Benedictines, and some few other monastic orders, as Dom Mabillon, Dom Calmet. The Spanish don, Portuguese dom, German von, and French de, are pretty well equivalent to it. (Latin, dominus.)