From the Old French form of the Greek name Eugenios (from eugenēs ‘well-born, noble’). This name was borne by various early saints, notably a 5th-century bishop of Carthage, a 7th-century bishop of Toledo, and four popes. It is sometimes used as an Anglicized form of Irish Eóghan and has also been used as an Anglicized form of the Irish name Aodh.
Irish: 1. reduced Anglicized form of Gaelic Ó hÉighnigh ‘descendant of Éighneach’ (see Heagney). 2. Anglicized form of Gaelic Ó hÉanna ‘descendant of Éanna’, a very common personal name of uncertain meaning. It was borne by various early saints, most notably St. Éanna of Aran. The name has been erroneously understood as containing the element éan ‘bird’ and as a result the surname was sometimes Anglicized as Bird.