Ó Maoldúin
Ó MAOLDÚIN—I—O Muldoon, Muldoon, Muldon, Meldon; 'descendant of Maoldúin' (chief of the fort); the name of several distinct families, as: (1) of an Oriel family who until the end of the 14th century were chiefs of Feara Luirg, now the barony of Lurg, in the north of Co. Fermanagh, and are still numerous in that county; (2) of a branch of the Ui Fiachrach in Co. Sligo; and (3) of a Thomond family.
Alphabetical Index to Irish Surnames