Mag Craith
Mag CRAITH—IV—MacGrath, MacGragh, Magrath, Magragh, Megrath, Magraw, &c.; 'son of Mac Raith.' This surname is frequently written Mac Craith (which see), but the most correct form is Mac Raith or Mag Raith (which see), under the latter of which the various families of the name are mentioned.
Alphabetical Index to Irish Surnames