Arthur, William (1857) An Etymological Dictionary of Family and Christian Names. New York: Sheldon, Blakeman. Public Domain.
DUNN
As described in historical dictionaries
An Etymological Dictionary of Family and Christian Names (1857)
Gaelic, Dun, a heap, hill, mount; a fortress, a castle, fastness, a tower. Dunn, Saxon, brown, of a dark color, swarthy.
Patronymica Britannica (1860)
DUNN. Dun, Dunne, Dunna, were A-Sax. personal names, and Done, Donne, &c. are in Domesd. Kemble considers them " adjectives relating to the dark
Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
Surname type: Nickname
Origin: English
Region of origin: British Isles
Country of origin: England
Religion of origin: Christian
Language of origin: English