travelling wave

Noun

 * 1)  A wave that is not bounded by a given space, but can propagate freely.
 * 2)  A wave in which the vibration is in the direction of propagation; a longitudinal wave.
 * 1)  A wave in which the vibration is in the direction of propagation; a longitudinal wave.

Translations

 * Chinese:
 * Mandarin: 行波
 * French: onde progressive
 * Japanese: 進行波