Patronymic was used by illegitimate royal children who were acknowledged as such by their fathers. The use of "Mac" in some form was prevalent in Scottish Gaelic, Irish and Manx, in all of which it denotes "son". "Mc" is also a frequent anglicisation in both Scotland and Ireland. In Ireland, the forms "Mag" and "M'" are encountered. The prefix "Mac" is used to form a patronym, such as "Mac Coinnich" – or the anglicized 'Mackenzie' – son of Coinneach/Kenneth. The female equivalent of "Mac" is "Nic", condensed from "nighean mhic" (in Scottish Gaelic) or "iníon mhic" (in Irish), both meaning daughter.
Kennedy (surname) Kennedy (surname) Kennedy, alternately O'Kennedy and Kennedie, is a surname of Irish and Scottish origin that has also been used as a given name. There have been several different etymologies given for the surname. One is that the name is an Anglicisation of "Ó Cinnéide", meaning "grandson of "Cinnédidh"" or "grandson of "Cinnéidigh"", with both of these personal names meaning "helmet headed." "Ceanéidigh" could be related to the old Gaelic name "Cennétig", which is known from Cennétig Mac Lorcáin, the father of the Irish high king "Brian mac Cennétig", who himself was also known as "Brian Bóruma" or Brian Boru.