(1):
(n.) 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.
(2):
(n.) Water thrown back by the turning of a waterwheel, or by the paddle wheels of a steamer.
(3):
(n.) An accumulation of water overflowing the low lands, caused by an obstruction.