Family name origins & meanings
- Northern Irish : Anglicized form of Gaelic Mac Dhonnchaidh ‘son of Donnchadh’, a widely used personal name meaning ‘brown one or chief of battle’, from donn ‘brown-haired’ or ‘chief’ + cath ‘battle’, which is Anglicized as Donagh or Duncan. Derivatives in which the personal name is unlenited include Donahue and McDonough; these derive from the early genitive form, Donnchadha. Forms ending in -y derive from the later genitive, Donnchaidh.