|Origin:||rivere, from Latin riparius 'of a river bank', from ripa 'bank, shore'|
a natural and continuous flow of water in a long line across a country into the sea [↪ stream]:
the Mississippi River
the River Thames
on a river
a boat on the river
along a river
We went for a walk along the river.
up/down (a) river
a ship sailing up river
They drifted slowly down river.
across a river
a bridge across the river
on the south bank of the river (=the land on one side of a river)
trees on the river bank (=the land next to a river)
The River Elbe flows through the Czech Republic.
at the mouth of the river (=where a river joins the sea)
a large amount of moving liquid
a river of hot lava flowing from the volcano