a tributary
An estuary.
The head source.
The river reaches the sea in its Estuary.
Haud verum
A place where a river rises is called the source or headwaters of the river. This is typically the point where the river begins, either from a spring, glacier, or other water source.
its called a coast tidal line.
It is called a delta. Or an estuary. It is the mouth of the river.
Brazilians call amazon river :river sea
The Tiber River runs through rome &:-}---------
There is a specific word in French for a river flowing into the ocean (as opposed to into another river), which is "fleuve" (masculine noun). A river which flows into another one is "une rivière" (feminine noun).
The River Colne is a small river that runs through Colchester.
what river runs along Detroit