Mcconaghy Family History

Irish (northern): Anglicized form of Gaelic Mac Dhonnchaidh ‘son of Donnchadh’ a widely used personal name meaning ‘brown one (i.e. chieftain) of battle’ from donn ‘brown-haired’ (in the transferred sense ‘chieftain’) + cath ‘battle’ which is Anglicized as Donagh (Ireland) or Duncan (Scotland).

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.