rapids

(from the article `waterfall`) ...to a series of small falls along a river. Still gentler reaches of rivers that nonetheless exhibit turbulent flow and white water in response to a ... ...flowing (lotic) and exhibit a longitudinal gradation in temperatures, concentration of dissolved material, turbidity, and atmospheric gases, from ... ...
Found on http://www.britannica.com/eb/a-z/r/13

Rapids

A reach of stream that is characterized by small falls and turbulent high velocity water.
Found on http://www.encyclo.co.uk/local/21804

Rapids

An area of broken, fast flowing water in a stream, where the slope of the bed increases (but without a prominent break of slope which might result in a waterfall), or where a gently dipping bar of harder rock outcrops.
Found on http://www.americantrails.org/

rapids

rapids 1. An extremely fast-moving or fast-flowing part of a river, caused by a steep descent in the riverbed. 2. The part of a river where the current moves with more celerity than the common current. A rapids is a section of a river where it loses elevation over a relatively short distance when the stream gradient is locally steepened, causing ...
Found on http://www.wordinfo.info/words/index/info/view_unit/1830/

Rapids

Rapids are fast-flowing stretches of water formed where the river surface breaks up into waves because rocks are near to the surface.
Found on http://www.encyclo.co.uk/local/21748

rapids

Turbulent stream water flow down a steep gradient, but not as steep as in a waterfall.
Found on https://www.encyclo.co.uk/local/22327
No exact match found