From Coastal Wiki
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.
- CIRIA (1996). Beach management manual, CIRIA Report 153.
- Morrison & Owen (1996). "The Planetary System", Addison-Wesley.