0 an area of very rough water caused by a raised area in the ground under the water, or by the meeting of two currents (= movements of water in a particular direction):
With its fierce currents and overfalls, this stretch of water is difficult to sail through.
The area is notorious for its tidal overfalls and treacherous reefs.
The force of the tides gives rise to overfalls and tidal races which can occur at different stages of the tide.
There is none of the danger of the heavy overfall of a following sea.
The dam measures 793 ft in length, with an overfall area that is 169 ft long.
The overfall area is faced on the downstream side with cut granite, and earthen embankment on the upstream side.
