Tarn, Corrie Loch, Mountain Lake

The word is derived from the Old Norse word tjörn meaning pond. Its more specific use as a mountain lake emerges as it is the commonly used term for all ponds in the mountainous areas of Northern England, particularly Cumbria. It retains a broader use, referring to any small lake or pond, regardless of its location and origin.
In Scandinavian languages a tjern or tjärn, tärn or tjørn is a small natural lake, often in a forest or with vegetation close around it or growing into the lake.