Douglas \do(ug)-las\ as a boy's name is pronounced DUG-less. It is of Scottish and Gaelic origin, and the meaning of Douglas is "black river". Place name. Historical: there were two branches of this powerful Scottish clan and family - the Black Douglases and the Red Douglases. The lords of these clans are key figures in Sir Walter Scott's novels. Actors Douglas Fairbanks, father and son; author Douglas Adams; General Douglas MacArthur.