meander

The formation of an oxbow lake. As a river meanders across a flood plain, the outer bends are gradually eroded and the water channel deepens; as the loops widen, the neck of the loop narrows and finally gives way, allowing the water to flow in a more direct route, isolating the old water channel and forming an oxbow lake.

Loop-shaped curve in a river flowing sinuously across flat country. As a river flows, any curve in its course is accentuated (intensified) by the current. On the outside of the curve the velocity, and therefore the erosion, of the current is greatest. Here the river cuts into the outside bank, producing a river cliff. On the inside of the curve the current is slow and so it deposits any transported material, building up a gentle slip-off slope. As each meander migrates in the direction of its outer bank, the river gradually changes its course across the flood plain.

A loop in a river's flow may become so exaggerated that eventually it is cut off from the normal course and forms an oxbow lake. Meanders are common where the gradient is gentle, the discharge fairly steady (not subject to extremes), and the material that is carried is fine sediment. The word meander comes from the name of the River Menderes in Turkey.