Family name origins & meanings
- Irish : reduced Anglicized form of Gaelic Ó Dúnadhaigh ‘descendant of Dúnadhach’, a personal name meaning ‘fortress-holder’ (from dún ‘fortress’, ‘fortified hill’).
- Irish : reduced Anglicized form of Gaelic Ó Maol Dhomhnaigh, or of Mac Giolla Dhomnaigh (see Maloney).
- Scottish : habitational name from the Scottish barony of Downie or Duny in the parish of Monikie in Angus (on Tayside), named from Gaelic dùn ‘hill’ + the locative suffix -ach.