The word “tsunami” comes from Japanese and literally means “harbour wave.”

More detail in brief:

  • It is made of two Japanese words: tsu = harbour, nami = wave.
  • The term was adopted internationally because many of these large waves have their most dramatic effects in harbours and along coastlines.

In modern English, “tsunami” is used for a very large sea wave usually caused by underwater earthquakes, landslides, or volcanic eruptions.