Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
MUIR
As described in historical dictionaries
Patronymica Britannica (1860)
MUIR. The Scottish form of JMoor. It occurs in composition with several surnames.
Origin: Celtic
Region of origin: British Isles
Country of origin: Scotland
Religion of origin: Christian
Language of origin: Gaelic