Ó Reachtagáin
Ó REACHTAGÁIN—I—O Raghtagan, Raghtigan, Ractigan, Ratican, Ratigan, Rattigan, Rhategan, Rhatigan, &c.; 'descendant of Reachtagán' (diminutive of reacht, law, decree); the name of an ecclesiastical family in Co. Roscommon, who were coarbs of St. Finnen, in the parish of Clooncraff, near Elphin.
Alphabetical Index to Irish Surnames