BAYOU (pronounced bai-yoo, probably a corruption of Fr. boyau, gut), an "ox-bow" lake left behind by a river that has abandoned its old channel in the lower stages of its course. Good examples are found in Palmyra Lake, in the Mississippi valley below Vicksburg, and in Osage river, Missouri. As a river swings from side to side in a series of curves which widen laterally where the current is slow and the country more or less level, there is a tendency in flood times for the water to impinge more strongly upon the convex bank where the curve leaves the main channel. This bank will be eaten away, and the process will be repeated until the base of the "isthmus" is cut through, and the descending channel meets the returning curve, which is thus left stranded and filled with dead water, while the stream runs directly past it in the shorter course cut by the flood waters that deepen the new channel, and leave an isolated ox-bow lake in the old curve.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)