eagre

n. high tidal wave in a river

A tidal bore (or just bore, or eagre) is a tidal phenomenon in which the leading edge of the incoming tide forms a wave (or waves) of water that travel up a river or narrow bay against the direction of the current. As such, it is a true tidal wave (not to be confused with a tsunami).Bores occur in relatively few locations worldwide, usually in areas with a large tidal range (typically more than 20 feet between high and low water), and where incoming tides are funnelled into a shallow, narrowing river via a broad bay. The funnel-like shape not only increases the height of the tide, but it can also decrease the duration of the flood tide down to a point where the flood appears as a sudden increase in the water level.
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Noun
1. a high wave (often dangerous) caused by tidal flow (as by colliding tidal currents or in a narrow estuary)
(synonym) tidal bore, bore, aegir, eager
(hypernym) tidal flow, tidal current

(n.)
A wave, or two or three successive waves, of great height and violence, at flood tide moving up an estuary or river; -- commonly called the bore. See Bore.
  

eager agree