Ó hAonghuis is an Irish surname, the original Gaelic form of the Anglicized Hennessy. It means "descendant of Aonghus," with Aonghus being a name of ancient Irish mythology and history. Etymology The surname Ó hAonghuis belongs to the widespread family of Irish patronymic surnames formed with the prefix Ó, meaning "grandson" or "descendant." The root name Aonghus comes from Old Irish Óengus, possibly meaning "one strength" from óen "one" and guss "force, strength." In Irish mythology, Aonghus (also called Mac Óg, "young son") was a god of love and youth, a member of the Tuatha Dé Danann, and the son of the Dagda and Boann. History and Bearers The cognate name Aonghus was borne by an 8th-century Pictish king, several Irish kings, and a few saints, including a 9th-century bishop of Tallaght. However, the surname Ó hAonghuis specifically denotes a descendant of someone named Aonghus. Like many Irish surnames, it was Anglicized during the English administration of Ireland, often taking the form Hennessy or other variants such as Guinness, MacGuinness, or MacGinnis. The distribution of the surname Ó hAonghuis itself is concentrated in Ireland, particularly in County Cork and surrounding areas, as indicated by surname frequency data. Cultural Significance The name connects to the deep well of Irish mythology through the god Aonghus, who was known for his poetic inspiration and romantic adventures. The surname thus carries an echo of that ancient heritage. It also reflects the broader pattern of Irish patronymic surnames that encode family lineage and Gaelic identity. Related Names Ó hAonghuis shares its root with several other surnames. In Scotland, similar forms include MacAonghais and its Anglicizations Angus, MacAngus, MacInnes, and McInnes. The variant Innes may also be related. The suffix of the name is retained in the variant Mag Aonghuis, which shows the lenition of the initial vowel. Meaning: descendant of Aonghus Origin: Irish Gaelic Type: patronymic surname Usage: Ireland (Gaelic form) Related Anglicized forms: Hennessy, Guinness, MacGuinness, etc.