BrennanIrish From Irish Ó Braonáin meaning "descendant of Braonán", a byname meaning "rain, moisture, drop" (with a diminutive suffix).
CampbellScottish From a Gaelic nickname cam beul meaning "wry or crooked mouth". The surname was later represented in Latin documents as de bello campo meaning "of the fair field".
DesmondIrish Anglicized form of Irish Ó Deasmhumhnaigh meaning "descendant of the man from South Munster", originally indicating a person who came from the region of South Munster (Desmond) in Ireland.