tributary

flows southwestward to become a tributary of the Mobile River

n a river in southeastern Siberia that flows northwest from Lake Baikal to become a tributary of the Yenisei River

a river in eastern Asia that arises in China and flows northeast along the border between China and Russia to become a tributary of the Amur River

a river that rises in the Rocky Mountains in Colorado and flows southeast through Kansas and Oklahoma and through Arkansas to become a tributary of the Mississippi River

a natural stream of water smaller than a river (and often a tributary of a river)