Arthur, William (1857) An Etymological Dictionary of Family and Christian Names. New York: Sheldon, Blakeman. Public Domain.
BUCHANAN
As described in historical dictionaries
An Etymological Dictionary of Family and Christian Names (1857)
(origin: Local) A parish in the shire of Sterling, Scotland. The derivation of the name is uncertain. It is probably from the same root as Buchan.
Patronymica Britannica (1860)
BUCHANAN. A jparish in co. Stii-ling, possessed by the fomily in early times.
Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
Origin: Celtic
Region of origin: British Isles
Country of origin: Scotland
Religion of origin: Christian
Language of origin: Gaelic