When the river enters the plain, it bends and flows forming large bends known as—

When a river enters the plain (its middle/lower course), it slows down and develops large bends called meanders. These curves are formed by lateral erosion on one side and deposition on the other. A levee is a natural embankment along the river, a floodplain is the flat land adjacent to the river that gets flooded, and an oxbow lake is a curved lake formed when a meander gets cut off from the main river.