​RIVER, any considerable stream of water flowing in a defined channel. The origin and subsequent formation of rivers and the valleys along which they How are considered under Geography, § Principles of Geography, and Geology, § viii. The word “ river ” is an adaptation of the O. Fr. rivere (mod. rivière), which descends through Med. Lat. rivera, Low. Lat. riparia, in the sense of river-bank and river, from ripa, bank. The Latin for a stream or river is rivus, whence rivulas, a small stream, Eng. “ rivulet,” which is, therefore, distinct in origin from “ river,” though probably the sense of rivus influenced the Med. Lat. rivera. The etymology of rivus and ripa is disputed; some scholars refer both to the root ri-), to drop, flow; others take ripa to be from the root seen in Gr. ἐρείπειν, to tear, English “ rive,” the sense being a broken cliff or steep bank.