It is from the Irish word mac, meaning "son of".
Traditionally, nobody was ever called Mac by itself; he was always MacSomething.
Mack Strong's birth name is Mack Carlington Strong.
Mack Brown's birth name is William Mack Brown.
Mack Jefferson's birth name is Larry Mack Jefferson.
Cedric Mack's birth name is Cedric Manuel Mack.
Hayward Mack's birth name is Hayward Seaton Mack.
Jillie Mack's birth name is Jillie Joan Mack.
Milton Mack's birth name is Milton Jerome Mack.
Stacey Mack's birth name is Stacey Lamar Mack.
Mack may be a nickname for the name Mackenzie. Mackenzie is a popular girls name and Mack is a way to shorten the name.
Mack Alston's birth name is Mack C. Alston Jr..
Mack Bates's birth name is Mack Curtis Bates III.
My friend's name is Mack...