Anglicized form of Gaelic Domhnall. The final -d of the Anglicized form derives partly from misinterpretation by English speakers of the Gaelic pronunciation, and partly from association with Germanic-origin names such as Ronald. This name is strongly associated with clan Macdonald, the clan of the medieval Lords of the Isles, but is now also widely used by families with no Scottish connections.
French: habitational name from any of various minor places so named, for example in Aisne, Côte d'Or, and Nièvre. The place name is from Romano-Gallic Billiacum, from a Gallic personal name Billios (Latin Billius) + the locative suffix -acum.