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family name (late 12c.), later masc. personal name, from Gaelic Dubh glas "the dark water," name of a place in Lanarkshire. Douglas fir named for David Douglas (1798-1834), Scottish botanist who first recorded it in Pacific Northwest, 1825. Douglas scheme, Douglas plan, Douglassite, etc. refer to "social credit" economic model put forth by British engineer Maj. Clifford Hugh Douglas (1879-1952).
municipal borough and capital, since 1869, of the Isle of Man, one of the British Isles. It lies on the island's east coast, 80 mi (130 km) northwest of Liverpool (across the Irish Sea). Low hills encircle the town, penetrated by the valley of the combined Dhoo (Manx, "dark") and Glass (Manx, "light") rivers, from which it takes its name.