Language descended from Old Frisian spoken on the North Sea coast of modern Netherlands and Germany from the 16th century until c. 1820.

A chain of islands in the North Sea, belonging to the Netherlands, part of the Frisian Islands.

A group of islands in the Wadden Sea, a part of the North Sea, off the western coast of Schleswig-Holstein, Germany.

(phonology) A sound change in the early Anglo-Frisian languages in which the vowel /ɑ/ was fronted to /æ/.