The river Buyuk Menderes Nehri was called Maiandros by the ancient Greeks. It winds its way through that part of modern Turkey known to the Greeks as Phrygia and flows into the Aegean Sea near Samos.
It pursues such a very winding, sinuous course that its name has been adopted as an adjective for any waterway that shows this tendency: a river, it is said, "meanders".
Most rivers have their origins in a mountain spring or lake. The stream, as it runs swiftly down the mountain gullies, follows a course that at first is reasonably straight. As it descends into the plain, however, and the slope of the ground becomes more gentle, nearer to the horizontal, the river broadens and its speed diminishes; this relatively flat terrain often results in a "meandering" path.
As a river flows on level ground, it erodes laterally rather than vertically; it grinds away at its banks on one side or the other, rather than trying to dig itself a deeper channel - and for a river, flowing in a straight line is not a stable situation. The slightest deviation, the merest gentle curve, requires the water to flow more quickly on the outside of the bend than it does on the inside.
This results in erosion of the river bank on the outside of the curve, and deposition of material in the relatively slow-moving water on the inside.
Over time, therefore, any slight bend in the river has a tendency to be enhanced; each curve becomes more and more pronounced until it can be recognised as a meander.
The best meandering occurs in river valleys, where a fine-grained cohesive soil and thriving vegetation make the outside of a bend relatively resistant to erosion. This slows the process sufficiently for deposition on the inside of a bend to keep pace with the retreating outside curve, allowing the river to maintain its coherence as it migrates - rather than just spread out into a series of untidy streams and pools.
Moreover, good meanderers, rather than lashing about wildly over a large area, tend to undulate back and forth over the centuries within a well-defined strip of ground, called the "meander-belt", defined by the terrain.
Sometimes a meander becomes so exaggerated and pronounced that only a narrow neck of land separates two adjoining portions of the river.
In such a situation, when the river flows more quickly in times of flood it may eventually cut right through this neck of land. Deposits later seal off the abandoned meander to create an isolated area of water in the shape of a horseshoe, a so-called "oxbow lake".