A tidal BORE is a natural phenomenon that occurs when the incoming TIDE meets an estuary or river, causing a large wave of water to travel upstream. The term 'tidal BORE' is derived from two words: 'TIDE' and 'BORE, ' which means 'wave.' The most famous example of a tidal BORE is the EAGRE, which is a five-letter word for a tidal BORE that occurs in the River Severn in England. Another example of a tidal BORE is the AEGIR, which is a five-letter word for a tidal BORE that occurs in the Bay of Fundy in Canada. Lastly, INFLOW is a six-letter word for the incoming TIDE that causes the tidal BORE.