Though the great bulk of these surnames have had an Irish, Scottish, or Welsh origin, a considerable number have come also from Cornwall, the Isle of Man, Brittany, and the other more Celtic parts of Northern France.
It was once traditional for everyone living in a Gaelic speaking district to have a local nickname describing his trade or a physical characteristic, e.g. “Donnchadh reamhar, an saor” (Fat Duncan, the Joiner) etc.
Meaning of surname Dougall: Dhu, black, and gall, a stranger