1590s, "of or pertaining to the people of Frisia," the lowland coast of the North Sea and nearby islands (Old English Frysland, Freslond; adjective Freisisc), named for the Germanic tribe whose name was Latinized as Frisii," which perhaps originally meant "curly-headed" (compare Old Frisian frisle "curly hair"). But Boutkan thinks it probably non-Indo-European. The Frisians emerged along the North Sea coast c. 700 B.C.E. and were known by name to Tacitus (the only people mentioned in his work still known by the same name). The native English form of the people name is Old English Frysan/Fresan (plural). Cognate with Old Frisian Frisa, Middle Dutch Vriese, Old High German Friaso). As a noun from c. 1600, "West Germanic language spoken in Friesland." It is closely related to Dutch and Old English.