Ó Foirtcheirn
Ó FOIRTCHEIRN—I—O Fortyerne, O Fortyn, Fortin, Fortune; 'descendant of Foirtcheirn' (an old Irish personal name, meaning 'over-lord,' doubtless the same as the British Vortigern); originally a Carlow surname, but now more numerous in Co. Wexford.
Alphabetical Index to Irish Surnames