the channel in which a stream flows or formerly flowed.

What is the meaning of streambed?

streambed, also called Stream Channel, any long, narrow, sloping depression on land that is shaped by flowing water. Streambeds can range in width from a few feet for a brook to several thousand for the largest rivers. The channel may or may not contain flowing water at any time; some carry water only occasionally.

Is stream bed one word?

stream•bed

n. the channel in which a stream flows or formerly flowed.