The Irish surname Heneghan is an Anglicisation of the Gaelic name O hEinachain (occasionally O hEanachain) and is also found in the variant forms Henaghan, Henihan and Henekan. The surname is generally regarded as being derived from the word éan meaning a 'bird', although this is questioned. Other possible sources are 'eanach' (more usually spelt 'aunach') meaning a 'fair' or 'meeting' at which the original bearer may have sold his wares, or alternatively 'eanach' meaning a 'watery place', in other words one who dwelt by a pond or a marsh.
The Heneghans were a sept of the Ui Fiachrach ('hunters'), a clan who dominated the Counties Mayo, Sligo and Galway in the Middle Ages. The Heneghans originally held land in Balla and Manulla in Mayo, and the county still claims the greatest number of the sept in Ireland with many of this surname resident in Carra and Clanmorris.
It is possible that a branch of the sept, or perhaps a completely distinct sept, dwelt in Kerry in the very south of Ireland, (a Tayg O Henehan was arraigned as a robber in this area in 1295). In the Seventeenth and Eighteenth Centuries the English ruling classes in Ireland frowned on the use of Gaelic surnames by the Irish, thus we find at this time that many Heneghans began to call themselves by the name Bird, a pseudo-translation from the Irish. We know of a family of the name Bird in County Dublin in 1607.
Occasionally the surname Heneghan is classed with Heaney or Heany which was also anglicised to Bird, although in fact the Heaneys were an ancient sept of Fermanagh, Armagh and Derry, and of different origin.
Argent, on a cross flory between four martlets gules, a mullet or, on a canton azure a cinquefoil of the field.
The martlet of the arms.
Dominus salus mea. (Translation: God is my salvation)