Water turned back in its course by an obstruction, an opposing current, or the flow of the tide, as in a sewer or river channel, or across a river bar.
- Water held or pushed back by or as if by a dam or current.
- A body of water thus formed.
- A place or situation regarded as isolated, stagnant, or backward: "The running of family fortunes has always been a backwater—albeit a lucrative one—of the investment management business” ( Business Week).
- A rowing or paddling stroke in which the oar or paddle is pushed forward, used to check a boat's forward motion or move it backward.