The River Glenderamackin is a river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 in the county

County

A county is a jurisdiction of local government in certain modern nations. Historically in mainland Europe, the original French term, comté, and its equivalents in other languages denoted a jurisdiction under the sovereignty of a count A county is a jurisdiction of local government in certain...

 of Cumbria

Cumbria

Cumbria , is a non-metropolitan county in North West England. The county and Cumbria County Council, its local authority, came into existence in 1974 after the passage of the Local Government Act 1972. Cumbria's largest settlement and county town is Carlisle. It consists of six districts, and in...

, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

.

The river rises on Mungrisdale Common and drains much of the eastern and southern sides of Blencathra

Blencathra

Blencathra, also known as Saddleback, is one of the most northerly mountains in the English Lake District. It has six separate fell tops, of which the highest is the Hallsfell Top.-Name:...

.

The river runs east, then north before sharply turning south at the village of Mungrisdale

Mungrisdale

Mungrisdale is a small village and civil parish in the north east of the English Lake District in Cumbria. It is also the name of the valley in which the village sits....

, skirting almost all around the bottom of Souther Fell.

Latterly, the river turns west at Lowside and is soon swelled by the waters of Mosedale Beck. The Glenderamackin continues past Threlkeld

Threlkeld

Threlkeld is a village and civil parish in the north of the Lake District in Cumbria, England, to the east of Keswick. It lies at the southern foot of Blencathra, one of the more prominent fells in the northern Lake District, and to the north of the River Glenderamackin.Historically a part of...

, at which point it conjoins with St. John's Beck

St. John's Beck

St. John's Beck is a river in the Lake District of Cumbria, England.The beck has its beginning as an outflow of Thirlmere, whence it flows northwards through St. John's in the Vale, towards Threlkeld, where it meets the River Glenderamackin to form the River Greta....

 to form the River Greta

River Greta

The River Greta is a river in Cumbria, England. It is a tributary of the River Derwent and flows through the town of Keswick.The source of the river is to be found near to Threlkeld at the confluence of the River Glenderamackin and St. John's Beck...

.

Etymology

The name "Glenderamackin" is of Brythonic derivation and is cognate with the Welsh

Welsh language

Welsh is a member of the Brythonic branch of the Celtic languages spoken natively in Wales, by some along the Welsh border in England, and in Y Wladfa...

 glyndwfr mochyn, meaning 'the river valley (glyndwfr) where swine (mochyn) live'.

This etymology is supported by the etymology of Mungrisdale, through which the river flows, featuring the same meaning from Norse.

The 'glendera' element is also present in the name of Glenderaterra Beck

Glenderaterra Beck

Glenderaterra Beck is a watercourse in the English county of Cumbria.The beck runs from its source on Burnt Horse through the valley between Lonscale Fell and Blencathra to its confluence with the River Greta at Brundholme near Threlkeld....

, which joins the River Greta shortly after its source.