The periodic rise and fall in the level of the water in oceans and seas as a result of gravitational attraction of the sun and moon and the rotation of the earth..
A more general definition from a geophysical viewpoint is
A tide is a distortion in the shape of a body induced by the gravitational pull of another nearby object..
The term 'tide' in the Coastal Wiki refers to the first definition.
The tide (more precisely, the astronomical tide) is the large-scale water motion generated by the rotation of the earth in combination with the varying gravitational influence on the ocean of celestial bodies, especially the moon and the sun. These phenomena cause predictable and regular oscillations in the water level, which are referred to as the tide. The astronomical tide at a specific location can be predicted and is published in Tidal Tables.
The term 'tide' is sometimes used for the combined effect of astronomical tide and wind-driven set-up or set-down of the sea level (including storm surges).
- CIRIA (1996). Beach management manual, CIRIA Report 153.
- Morrison & Owen (1996). "The Planetary System", Addison-Wesley.