friesic

 Of or pertaining to Friesland, a province in the northern part of the Netherlands.  [1913 Webster]

 The language of the Frisians, a Teutonic people formerly occupying a large part of the coast of Holland and Northwestern Germany. The modern dialects of Friesic are spoken chiefly in the province of Friesland, and on some of the islands near the coast of Germany and Denmark.  [1913 Webster]