Meaning:
Its source is Donnchadh, a Gaelic name meaning "Brown soldier."
Popularity:
The name Duncan ranked 486th in popularity for males of all ages in a sample of 2000-2003 Social Security Administration statistics and 803rd in popularity for males of all ages in a sample of the 1990 US Census.
Though this name appears on the 1990 U.S. Census lists, it is used by only a small percentage of the general population.