la Garonne
the river mouth
The mouth is where the river enters the sea.
The source of a river is where it begins, the mouth of a river is where it enters the sea.
Mouth of a River
The mouth
The point at which the river ganges enters the sea
It is the river's mouth
Answer 1The point at which a waterway [creek, river, etc.] enters another body of water [stream, lake, sea, ocean, etc.] is called the "river mouth."
The 'mouth' or 'delta'.
Amazon River
Usually it would be an estuary.
A delta is a body of sediment deposited at the mouth of a river or stream where it enters an ocean or lake.