McLaughlin (surname) McLaughlin (surname) M(a)cLaughlin is the most common English form of "Mac Lochlainn", a masculine surname of Irish origin. The feminine form of the surname is "Nic Lochlainn". The literal meaning of the name is "son of "Lochlann"". Note that "Mc" is simply a contraction of "Mac", which is also (albeit rarely) truncated to "M' ". Thus, "MacLaughlin", "McLaughlin" and "M'Laughlin" are the same Anglicism, the latter two merely contractions of the first. The original surname Mac/Nic Lochlainn was borne by a family of Cenél nEógain, a branch of the historic northern O'Neill dynasty, reputedly founded by Niall Noígíallach. This family
Mac and Mc together in print two publications on filing rules, one covering that "word-by-word" convention, and another prepared in 1980 that is "letter-by-letter". A 1998 book attributes the changes to the rules to computer informatics, and notes the Mac/Mc change as its first example. 1982's "Scottish Roots", a guide for family history researchers, warns that older Scottish records do not in fact follow this convention, unlike contemporary telephone directories. A 2001 book of "New York Times" theatre reviews sorts Mc names as if spelled Mac. A 2002 official document for the State of Vermont recommends explicitly no special treatment for Mac and Mc.