Frisland appears as a name of an island south of Iceland on many old maps depicting the North Atlantic region. In Nicolo Zeno's book and map of 1558 it is very prominent. Frisland was probably an amalgamation of Iceland and the Faroes and the double of both of them.
This map is from Corso geografico universale by Vincenzo Coronelli and is probably derived from the Zeno map.