It is called a tributary.
tributaries
Tributaries
It Joins at a confluence. That is where the river joins the larger one.
Most countries will have a small river. What is the name of the river?
It's known as a 'tributary'
The smaller river is a tributary to the big one.
carthageth
Tributary.
The Kalamazoo River.
Tributary
The diameter is much larger than the small intestine.
mouth