Ó Tanaidheáin
Ó TANAIDHEÁIN—I—Tannian, Tannion; 'descendant of Tanaidheán' (diminutive of tanaidh, thin, slender); a rare Connacht surname. In 1406, Turlough oge O'Connor, King of Connacht, was slain by Diarmaid Ó Tanaidhen.
Alphabetical Index to Irish Surnames