Ulaid is a plural noun and originated as an ethnonym, however Irish nomenclature followed a pattern where the names of population-groups and apical ancestor figures became more and more associated with geographical areas even when the ruling dynasty had no links to that figure, and this was the case with the Ulaid. Ulaid was also known as "Cóiced Ulad", the "Fifth of Ulster", and was one of the legendary five provinces of Ireland. After the subsequent loss of territory to the Airgíalla and Northern Uí Néill, the eastern remnant of the province that formed medieval Ulaid was alternatively known as "in Cóiced", in reference to the unconquered part of "Cóiced Ulad".