Ó Dúnáin
Ó DÚNÁIN—I—O Doonan, Doonan, Donnan; a variant of Ó Donnáin, which see; a scattered surname, but now found chiefly in Leitrim and Roscommon. Maolmhuire Ó Dúnáin was Bishop of Cashel in the early part of the 12th century.
Alphabetical Index to Irish Surnames