Clan Douglas
Linguistically, "Douglas" is derived from the Gaelic elements: "dubh", meaning "dark, black"; and "glas", meaning "stream" (also a derivative of "glas", meaning "green"). The surname "Douglas" is a habitational name, which could be derived from any of the many places so-named. While there are numerous places with this name in both Ireland and Scotland, it is thought, in most cases, to refer to Douglas, South Lanarkshire, which was once the stronghold of Clan Douglas.