Arthur, William (1857) An Etymological Dictionary of Family and Christian Names. New York: Sheldon, Blakeman. Public Domain.
NANCE
As described in historical dictionaries
An Etymological Dictionary of Family and Christian Names (1857)
(origin: Local) From Nance or Nancy, a city of France, capital of the department of Meurthe, and signifies a valley; nans or nantz, in the Cornish British, is a plain, a dale, a level.
Patronymica Britannica (1860)
NANCE. An estate in the parish of Illogan. CO Cornwall, which was, not many generations since, in the possession of the family.
Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
Surname type: Location or geographical feature
Origin: English
Region of origin: British Isles
Country of origin: England
Religion of origin: Christian
Language of origin: English