1》 a large natural flow of water travelling along a channel to the sea, a lake, or another ~.
↘used in names of animals and plants living in or associated with ~s, e.g. ~ dolphin .
2》 a large quantity of a flowing substance.
sell someone down the ~ informal betray someone. [orig. with ref. to the sale of a troublesome slave to a plantation owner on the lower Mississippi, where conditions were relatively harsher.]
up the ~ N. Amer. informal to or in prison. [with allusion to Sing Sing prison, situated up the Hudson River from the city of New York.]
River comes via Old French ~e from Latin riparius , from ripa 'bank of a ~'. It is related to arrive , which originally meant 'bring a ship to shore'. It is also connected to the word rival , which derives from Latin rivalis , originally meaning 'person using the same stream as another', from rivus 'stream'. Riviera , an Italian word ultimately derived from Latin ripa , preserves the original meaning of 'land next to water'.