Henehan, Heneghan, ó hEineacháin A Gaelic surname meaning descendant of Eidhneachán. A sept of the Ui Fiachrach, who were formerly seated in the parishes of Manulla and Balla in Mayo. ó hEanacháin is a variant. Somtimes anglicised Bird, being erroneously supposed to be derived from ean meaning a ‘bird’. In 1890 the surname was principally found in Mayo and the estimated number of bearers was 2,200.