Ó Reannacháin
Ó REANNACHÁIN—I—O'Renahan, Ranaghan, Reneghan, Renihan, Rinaghan, Rinahan, Rinihan, Ranahan, Renehan, Renahan, Ronaghan, &c., Ferns, Ferrons 'descendant of Reannachán' (dim of reannach, spear-like); Compare with Mag Reannacháin.
Alphabetical Index to Irish Surnames