1. A wave that moves relative to a fixed coordinate system in a fluid; or, in meteorology, a wave or wavelike disturbance that moves relative to the earth's surface. Progressive waves are to be distinguished from stationary waves, which show no relative translation. Standing waves can be treated mathematically as two equal and oppositely directed progressive waves superimposed upon each other. 2. In oceanography, a wave the travel of which can be followed by monitoring the movement of the crest. Energy is transmitted; that is, the wave form travels significant distances, but the water particles perform oscillatory motions. See also Kelvin wave.