Mac means son of so MacDonald is son of Donald.
In Irish names "Mac" means "Son" and "Ó" means "Grandson"
Last names beginning with "Mc" or "Mac" are of Irish origins.
The meaning is not clear. It was a name popularized by Americans during the 1990's who wanted a name that sounded similar to Aiden. Some reason it to be an Anglicized and reduced derivative of the Irish Gaelic surname Mac Cadáin meaning "son of Cadán".
Costello is Irish Gaelic in origin. It is an Anglicized form of the name "Mac Oisdealbhaigh" or "Son of the one that resembles a deer".
The Scottish Gaelic form was Mac'Ille Bhàin which translates "son of the servant of the fair-haired one". If an Irish Gaelic name it would be Mac Giolla Bháin.
'Ap' means 'son of', similar to Irish 'Mac'.
It is estimated that about 20% of Irish surnames have a Mac prefix. Mac means son; so Mac Carthaigh would mean 'son of Carthach'.
The Irish Gaelic name Mac Óda is derived from their ancestor Odo Archdeacon.
Son of Rory (Mac Ruairí in Irish).
The Irish Gaelic name Mac Óda is derived from their ancestor Odo Archdeacon.
In Irish Mac Maghnuis (son of Magnus) from the Latin word for 'great'.
Originally Mac it means 'son' in Scottish Gaelic and Irish.
John (Mac)Corish As regards Mac Fheorais, I am certain that it is the Irish Gaelic equivalent of the Anglo Irish name Bermingham.
The name Egan (Keegan) is an Anglisization of the Irish name Mac Aodhagáin, an Irish clan that were hereditary lawyers.
"Mac" or "Mc" means "son". Found in Irish and Scottish Highland surnames. Mac Néill is "son of Niall".
When seen as a prefix in a surname, Mac or Mc means "Son of".
Son of