Place where river begins
tributary
river source
riber basin
confluence
Stream or river which joints a larger river
river mouth
estuary
watershed
Place where a river enters the sea, a lake or other river
river course
river basin
Part of the river mouth which is tidal
Total area drained by a river and its tributaries
the high ground which separates one river basin from another
the place where 2 or more river meet
the route taken by a river between its source and its mouth