Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
ENNIS
As described in historical dictionaries
Patronymica Britannica (1860)
ENNIS. A contraction of the Irish Mac Gennis.
Origin: Celtic
Region of origin: British Isles
Country of origin: Ireland
Religion of origin: Christian
Language of origin: Gaelic