👉 A billow is a type of wave that occurs when water flows over a smooth surface, such as a river or lake. The movement of water causes it to expand and spread out in an upward direction, creating a similar effect to a cloud rising above the water's surface.
Billowing waves can be caused by various factors, including the flow of moving water, the resistance of the water to gravity, and the movement of the land around the river. The frequency and strength of the billow will
billowiness