A tidal bore,[1] often simply given as bore in context, is a tidal phenomenon in which the leading edge of the incoming tide forms a wave (or waves) of water that travels up a river or narrow bay, reversing the direction of the river or bay's current. It is a strong tide that pushes up the river, against the current.
- ^ Sometimes also known as an aegir, eagre, or eygre in the context of specific instances in Britain.