Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
LEAN
As described in historical dictionaries
Patronymica Britannica (1860)
MAC LEAN. Originally Llacgillean. From a celebrated Highland warrior, Gillean-in-Tuiodh, or Gillean of the Battleaxe. B.L.G. Gaelic etj-mologists say,il«c-a(jldlle-leathan — "the sou of the Broad Lad !"
Surname type: From given name or forename
Origin: Celtic
Region of origin: British Isles
Country of origin: Scotland
Religion of origin: Christian
Language of origin: Gaelic