A megatsunami is a terrifying event where waves that can reach hundred of meters high, are generated by a massive landslide, volcanic explosion, or Earthquake. However, there are various synonyms that are being used for this word. Some of the synonyms of megatsunami include mega-wave, giant tsunami, monster wave, giant tidal wave, tidal wave, storm surge, and wall of water. These words represent the destructive power and enormous size of these waves. Whatever the term used, however, a megatsunami is an awe-inspiring and potentially deadly force of nature that is feared by those living in coastal areas.