An ancient region of north-western Europe. It consisted of the Frisian Islands and parts of the mainland corresponding to the modern provinces of Friesland and Groningen in the Netherlands and the regions of Ostfriesland and Nordfriesland in north-western Germany.
Definition of Frisia in US English:
Frisia
proper nounˈfrēZHə
An ancient region of northwestern Europe. It consisted of the Frisian Islands and parts of the mainland corresponding to the modern provinces of Friesland and Groningen in the Netherlands and the regions of Ostfriesland and Nordfriesland in northwestern Germany.