The word Dominus was used as an equivalent for the Greek κυριος, and thus became a Divine title when places of worship becoming known as the House Domini (of the Lord), the term duomo, domnach, and dom in Italy, Ireland, and Germany adhered to the chief mother church of the diocese, and is now applied to cathedrals; whilst from the peculiar cupola of Italian duomi of the Romanesque or Byzantine period, we have taken our word dome, applied to form alone.
    Dominicus, the adjective formed from this word, is found in the French term for the Lord's Prayer, l'Oraison Dominicale, and it likewise named the Lord's Day, Dies Dominica;... (History of Christian Names, Yonge, 1884).