Twatt is the name of a district on the Orkney Mainland. It was previously the location of a RNAS airfield, HMS Tern, 1940–1949. The name originates from the Old Norse þveit, meaning 'small parcel of land'. The Norse word commonly produces in England the place name element Thwaite. It's also a surname in Orkney, although getting less common as people with it tend to drop the first "T" and become "Watt".