Arthur, William (1857) An Etymological Dictionary of Family and Christian Names. New York: Sheldon, Blakeman. Public Domain.
KAVANAGH
As described in historical dictionaries
An Etymological Dictionary of Family and Christian Names (1857)
(origin: Celtic or Gaelic.) Coamhanach, mild, benevolent, merciful; a friend, a companion. Mr. John O'Donovan says, that Donnell Cavanagh was so called from having been fostered by the Coarb of St. Cavan, at Kilcavan, in the present county of Wexford, Ireland.
Origin: Celtic
Region of origin: British Isles
Country of origin: Ireland
Religion of origin: Christian
Language of origin: Gaelic