Ameander that has been cut off from the river becomes a

Salutations!

A meander that has been cut off from the river is called oxbow lake. I will now give an explanation on how an oxbow lake is formed.

An oxbow lake is a narrow U-shaped lake near a river. Its a meander that got cut off.

As erosion, continues, the neck of the meander is worn away. It gets narrower and narrower. Then, during flooding, the river takes a shortcut - straight across the neck. Soon the loop of the meander gets sealed off. It turns into an oxbow lake. In time, the lake will get covered with weeds, and fill with soil, and disappear. 

Hope I helped (:

Have a great day!