or FOUL Island, one of the Shetland isles, lying between six and seven leagues west from the main land. It is about three miles long, narrow, and full of rough, steep, and bare rocks; one of which is so large, and runs up to such a height, that it may be clearly seen from Orkney. This, it is probable, is the Thule of Tacitus. It has scarcely any pasturage, and but little arable land. The only commodities exported are stock fish, train oil, and feathers.