DOUGALL

(origin: Gaelic and Celtic.) The black stranger, from Dhu, black, and gall, a stranger, a term used by the Celts to denote a Lowlander, a foreigner, not one of them. The Danes, Swedes, and Norwegians were called by the Irish Fionne Gael, or fair-haired, and the Germans "Dubh Gail," or the black strangers.

Arthur, William (1857) An Etymological Dictionary of Family and Christian Names. New York: Sheldon, Blakeman. Public Domain.

DOUGALL. (Generally Mac-Dougall). Gael, dint, black, and (all, a stranger — an expression used by the Celtic inhabitants of Scotland to denote a Lowlander, or any one not of their own race. It is still in use as a baptismal name.

Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.