A sound wave is a vibration that propagates an acoustic wave. It has a second meaning, which is:A sound wave is a pattern of disturbance caused by the movement of energy traveling through a medium as it moves away from the source of the sound. The density of a medium affects the speed of the sound wave and usually when particles are closer sound is more muffled and travels slower.
Sound travels through sound waves
Meaning of propagates: the action of widely spreading