The wave that spreads behind a boat as it moves forward WordNet 3.0 & Open English WordNet

In fluid dynamics, a wake may either be: the region of recirculating flow immediately behind a moving or stationary blunt body, caused by viscosity, which may be accompanied by flow separation and turbulence, or the wave pattern on the water surface downstream of an object in a flow, or produced by a moving object, caused by density differences of the fluids above and below the free surface and gravity. Wikipedia

The region of recirculating flow immediately behind a moving solid body Wikipedia Disambiguation

The wake pattern produced by waterfowls, boats, etc. crossing water, consisting of two wake lines that form the arms of a V, with the source of the wake at the point. Wiktionary

The area behind something, typically a rapidly moving object. Wiktionary